The Mexican War and World War I on the Conflict Continuum

Introduction

Joint Publications 3-0 Joint Operations includes a framework¹ for understanding both the varieties of miliary and military/civil operations as well as the phases of such operations. The foundation of this framework is the “conflict continuum”, the realization that peace and war aren’t the only two possible relations that can exist between nation-states, that other relations are possible, such as crisis response, security cooperation, etc. The purpose of this paper is to look at the Mexican-American War and World War I through this framework.

We begin with an explanation of manifest destiny, and how this policy drove the United States and Mexico into conflict. For purposes of evaluating the Mexican-American War along the conflict continuum, a history of that war is supplied.

A similar approach is taken with World War I: the history of WWI prior to our declaration of war is given, the reasons for our involvement are explained, and a brief description of the way we worked with the Allies is explained.

Next, the conflict continuum itself is described, including the phases a military operation moves through from beginning to end, and some of the examples of not-strictly combat operations are given. The Mexican-American War and World War I are then evaluated using this knowledge of the conflict continuum to classify the two wars and the phases they went through.

The concluding section recaps how these two wars demonstrate some of the finer points of JP 3-0, as well as a certain “slipperiness” in the shaping phase.

The Mexican-American War

In the mid 19^th century, a belief called “manifest destiny” became an informal American foreign policy². Advocated by various journalists and newspaper editors and adopted by certain politicians, manifest destiny called for the spread of freedom and American ideals westward through various means, including territorial acquisition. This is the context underlying US-Mexican diplomatic relations at the time and in part lead to the Mexican-American War.

Mexican territorial claims relinquished in the Treaty of Guadalupe Hidalgo and the Gadsden Purchase

The Mexican War started³ over a dispute about the location of Texas’s border, and by extension the southern American border. The Republic of Texas declared its independence from Mexico in 1836 and joined the United States on 29 December 1845, becoming the 28^th state. Mexico did not recognize Texas’ succession, and so when it became a member of the Union, we inherited the ongoing border dispute.

Again, where was Texas’ southern border? Mexico claimed the border should be the Nueces River, whereas America believed the border should be south of that, at the Rio Grande.

President James Polk offered to purchase⁴ the land north of the Rio Grande and west of Texas all the way to the Pacific Ocean for $25 million, but Mexico refused – Mexico was undergoing internal rebellions at the time, so it may not have been possible to accept payment.

To pressure Mexico to accept the purchase, Polk dispatched Pacific Squadron ships to blockade Mexico along the California coast and the Home Squadron to blockade Mexico’s Gulf coast. He also sent troops into the disputed Texas territory under the command of General Zachary Taylor.

On 25 April 1846, Mexican cavalry attacked Taylor’s troops. The Mexicans then attacked American forts on the Rio Grande. Taylor called for reinforcements and were able to defeat the Mexicans in the Battle of Palo Alto and the Battle of Resaca de la Palma. Polk lost all patience with Mexico at that point, and on 13 May of that year, Congress declared war.

While Taylor worked south, General Stephen Watts Kearny entered what would later be called New Mexico and captured Santa Fe without encountering any Mexican military forces. On 25 September 1846, Kearny left New Mexico under civilian government (with military support) and set out for California.

As this was happening, the Pacific Squadron received orders to blockade San Francisco Bay. Command of the squadron was transferred to Commodore Robert F. Stockton, and continuing south, his land forces entered Los Angeles without encountering opposing forces.

Kearny’s march continued. He crossed the Colorado River and engaged Mexican forces at the Battle of San Pasqual in modern-day California on 6 December 1846. He was trapped in a defensive position until American relief forces arrived. Kearny was then able to complete his march to Los Angeles.

On 8 January 1847, Kearny’s and Stockton’s forces engaged the Mexicans at the Battle of Rio San Gabriel. The Mexicans retreated and the next day they fought again at the Battle of La Mesa. The Mexicans were defeated, and this led to the Treaty of Cahuenga. This treaty ended the conflict in California but fighting continued south of Texas.

Zachary Taylor’s army continued into Mexico which led to Battle of Rio Monterrey on 21-24 September 1846. This was an urban battle (our first urban warfare experience since the Revolutionary War⁵), and we were defeated. An armistice was declared, but under orders from Washington, Taylor broke the armistice and continued marching south. He encountered General Antonio López de Santa Anna at Puerto de la Angostura. The resulting battle, the Battle of Buena Vista, lasted for two days, from 22-23 February 1847. Santa Anna retreated to Mexico City to put down an insurrection in Mexico City.

By this time, President Polk realized that occupying northern Mexico was insufficient to get Mexico agree to the purchase. An invasion of the Mexican interior was necessary. To this end, General Winfield Scott arrived off Veracruz by sea to begin the invasion on 9 March 1847. Scott performs first major amphibious landing in US history⁶ as part of the Siege of Veracruz. Mexican forces surrendered.

Scott then marched westward towards Mexico City. Santa Anna set up a defensive line close to Veracruz, but Scott sent cavalry ahead. The two forces met on 18 April 1847, and the Battle of Cerro Gordo ensued. Santa Anna again retreated to Mexico City with Scott laying chase.

Scott arrived at Mexico City and after defeating Mexican forces at the Battle of Contreras and the Battle of Churubusco (both ending on 20 August 1847), peace negotiations began. Negotiations broke down on 6 September 1947, however. In response, Scott fought additional battles (the Battle of Molino del Rey and Battle of Chapultepec) which led to the storming of the city gates and the capture of Mexico City.

The war ended on 2 February 1848 with the signing of the Treaty of Guadalupe Hidalgo. This treaty gave us control not only over Texas to the Rio Grande, most of New Mexico, and all of California and Utah, but also parts of Arizona, Colorado, Oklahoma, Kansas, and Wyoming. In return, Mexico received $15 million, approximately half of Polk’s original offer⁷.

The remainder of Arizona and New Mexico were purchased in 1854 from Mexico for $10 million. With this purchase, called the Gadsden Purchase, the current position of the US southern border was established.

World War I

Nothing as grandiose as manifest destiny drove us into World War I. Rather our involvement was the result of an accumulation of events that included threats to maritime traffic, possible collusion between Mexico and the Central Powers, as well as ensuring the repayment of loans made to France, Britain, and Italy⁸.

The “Great War” was preceded by the assassination of Austrian Archduke Franz Ferdinand, heir presumptive to the throne of Austria-Hungary, and his wife on 28 June 1914 by a Serbian political activist while they were in Sarajevo. This led to the July Crisis, a series of military escalations and diplomatic incidents among the major European powers, which led to Austria-Hungary declaring war on Serbia on 28 July 1914, marking the start of World War I. By August of that year, Austria-Hungary, Germany, Serbia, Great Britain, France, and Russia as well as Japan were at war. The Ottoman Empire entered the war on the side of the Central Powers on 31 October 1914, and Italy joined the Allied Powers on 23 May 1915.

Before Italy joined, war spread to European colonies, with Britain invading German East Africa on 3-5 November 1914. This battle, The Battle of Tanga (also called “The Battle of the Bees”) marked the beginning of Lieutenant Colonel Paul Emil von Lettow-Vorbeck’s African campaign⁹.

The United States attempted to stay militarily neutral while continuing economic trade with France, Britain, and Italy. In addition, American bankers made loans those nations. Early events in the war, especially the sinking of the RMS Lusitania by a German U-boat on 7 May 1915 resulting in the loss of 128 American lives, foretold that the United States would not be able to maintain neutrality¹⁰.

There were three events that lead America to enter the war on the side of the Entente: Germany’s breaking of the Sussex Pledge, the increasing likelihood that the Central Powers would be victorious, and the Zimmerman Telegram.

Following the sinking of several civilian vessels by German naval vessels early in the war, Germany issued the Sussex Pledge to the US on 4 May 1916. In this pledge, Germany made the following changes to its rules of naval engagement: passenger ships would not be targeted; merchant vessels would not be attacked unless inspection showed the presence of weapons; and merchant vessels would not be targeted unless those aboard could be rescued.

Eight months later, over the objections of the German Chancellor, the German navy convinced military leaders and Kaiser Wilhelm II that unrestricted submarine warfare could be used to defeat the Entente before the US entered the war¹¹. The Pledge was thus rescinded in January 1917.

The February 1917 Revolution in Russia indicated that due to political instability, Russia’s continued participation in the war could not be guaranteed. Russia was wavering, and the odds of the Central Powers winning increased. If they won, then the European Allies would (presumably) be unable to repay the loans that American bankers made to them.

Indeed, the October 1917 Revolution and the subsequent Civil War led to the Bolsheviks obtaining power. Vladimir Lenin signed a peace treaty with the Central Powers, the Treaty of Brest-Litovsk, on 3 March 1918. With Russia no longer involved, Germany turned its attention to France and Great Britian.

In January 1917, Britain intercepted and decoded a telegram sent from the German Foreign Minister Arthur Zimmermann to the German Minister to Mexico, offering US territory to Mexico should the enter war on the side of the Central Powers. The British then sent the telegram to the United States on 24 February. It was made available to the American public on 1 March¹².

On 6 April 1917, two years and eight months following the outbreak of war, the United States entered World War I on the side of the Allies. The first parts of the American Expeditionary Force (AEF) arrived in June 1917 and continued to arrive over the next four months.

At this point in the war, the Allies and Central Powers were at a stalemate: 430 miles of trenches were dug between France and Germany, running from the North Sea and the Swiss border, and those trenches mostly remained fixed for over two years. This was well illustrated by the Battle of Verdun, lasting from 21 February to 18 December 1916, making it the longest battle of the war, and by the end there was little change in positions of the lines. Despite the use of chemical weapons, tanks, and aerial bombings, the Western Front remained in a deadlock, with neither side able to gain and hold territory.

The question then became how the US military would break this stalemate.

French and British military leaders initially wanted American forces to supplement the Allied ranks in a policy called “amalgamation”, essentially turning them into cannon fodder. General John J. Pershing, commander of the AEF, objected, refusing to allow his troops to be under the command of non-Americans¹³. Further, he rejected trench warfare and insisted on using “open warfare” which would capitalize on American mobility, aggressiveness, and marksmanship. Pershing did permit AEF troops to train with the French, however, before going into combat.

General John J. Pershing

Pershing’s requirement that American warriors operate under a completely American chain of command became a staple of future joint operations: Americans would fight alongside foreign troops, not under them.

As the AEF continued to arrive, larger and larger military operations were executed, culminating in the Meuse-Argonne Offensive. This was the largest operation of the war, the goal of which was to evict German troops from France by attacking them along the entire Western Front. The battle began on 26 September 1918 and continued for 47 days. Pershing rotated his troops not only to maintain their strength but also so they could train incoming troops. In November, Americans advanced as fast as logistics allowed, at one point even advancing off the AEF headquarters’ maps.

The Meuse-Argonne Offensive ended when news of the Armistice arrived on 11 November 1918. This marked the end of World War I.

Fitting Those Wars into the Conflict Continuum

JP 3-0 explains that military conflict occurs on a “spectrum” or “continuum” with peace at one side and war at the other. This is of fundamental importance, as the authors of JP 3-0 are rejecting the idea that peace and war are the only two conditions that can exist between nations and other actors¹⁴. This idea is expanded in two ways: first, a joint operations model - an analysis of the progression of events as nations move about this continuum; second, a listing of some types of military operations that can include conflict but can also include military operations other than war (MOOTW).

The joint operation model¹⁵ describes how the United States and Partner Nations (PN) can prepare for conflict, conduct conflict, then end a conflict. There are six phases in the model:

Shape – activities to set the conditions for successful in-theater operations; shaping activities are primarily political (e.g. coalition building, securing overfly and navigation rights) but can also include multinational training exercises, intelligence sharing, etc.

Deter - Prevents adversaries (traditional, non-state actors, etc.) from either creating or capitalizing on a crisis.

Seize Initiative - Utilize all capabilities as early as possible to delay, impede, or halt enemy's initial aggression and prevent him from achieving his initial objectives. Ideas is to expand freedom of action of friendly forces (by, e.g. accessing and controlling infrastructure in theater) as well as degrading enemy's capabilities with the goal of resolving the crisis as soon as possible.

Dominate - Break enemy's will to resist by overmatching enemy's capabilities at critical times and places.

Stabilize - (Re)establish a secure environment, which can include (re)building infrastructure.

Enable Civil Authority - Support legitimate governance following conflict.

This six-stage model can be applied to other types of operations, including humanitarian assistance operations. Additional phases may be added depending on the type of operation, and it is the JFC that sets criteria for the transition between phases¹⁶.

The conflict continuum can also include MOOTW, and JP 3-0 provides examples of these types, including noncombatant evacuation, foreign internal defense, counterdrug operations, and so on¹⁷. It is possible for an operation to move between these types: for example, the Afghanistan War began as a military engagement, then transformed to a combination of counterinsurgency and defense support of civil authorities.

Of the examples of military operations and activities listed in JP 3-0, the Mexican-American War would count as a military engagement. The shaping phase included Polk’s initial offer to purchase the territory is described above. The blockade established along Mexico’s Gulf and California coasts as well as the placement of troops south of the Nueces River constituted the deter phase. Seizing initiative and domination phases are the parts where Taylor moved south of the Nueces River, Kearny’s march into California, and Winfield Scott’s amphibious landing and march to Mexico City.

Kearny’s activities in New Mexico demonstrate both stabilization (his initial establishment of a military government in Santa Fa) and the enabling of civil authority (leaving a civilian government in place along with military support).

With the capture of Mexico City, Scott “imposed martial law, maintaining order through an even-handed policy that treated U.S. troops and the Mexican populace equally.¹⁸” This would count as stabilization. It isn’t clear how the Unites States enabled civilian authority, though perhaps the final payment of $15 million helped in that regard.

World War I was different in that we were not involved in the conflict until 32 months after it started. Although for us it was certainly a large-scale combat operation, we initially played a supporting role until AEF arrived in full and found its stride. So, while we were not present at the beginning, the Allies (PNs) were. Thus, the shape and deter phases were performed (or, rather, not performed) by the Allies. Our entrance was at the dominate phase. Following the end of hostilities, our participation became one of foreign humanitarian assistance, with the American Relief Administration¹⁹ providing massive amounts of relief supplies to Europe.

Conclusion

The two wars examined in this paper help to illuminate both the breadth and some of the subtilities of the conflict continuum framework given in JP 3-0.

Unlike WWI, the Mexican-American War was not a joint operation. JP 3-0 is still applicable though; the war was a joint operation where there were no partner nations – it was a coalition of one.

WWI demonstrated that in a joint operation, the United States need not be an active participant of every phase of conflict – it is sufficient that at least one PN engages in a given phase and passes the results on to the other members of the coalition. We entered that war over two years after it started, and we had to build upon the work the other partner nations either completed or were in process of completing.

As WWI ended, what was a large-scale combat operation became a humanitarian operation, showing that it is possible for a military operation or activity to change type as events unfold.

WWI also demonstrated the need for establishing a clear chain of command among partner nations, and that this chain of command must not result in an American service member being under command of a non-American coalition member. Pershing was adamant in this, and this prevented American troops from being used to prolong the stalemate instead of acting decisively to bring the war to a conclusion.

Finally, a certain ambiguity in the conflict continuum must be identified. According to JP 3-0, “shaping activities help set conditions for successful theater operations,” and that in the best case, “shaping activities may avert or diminish conflict.” The preparations President Polk made prior to the start of the Mexican-American war can technically be called shaping activities, but instead of either preventing war or helping ensure that operations are successful, Polk’s shaping operations became a threat²⁰, and the price of ignoring that threat was war. 

Footnotes

1. Joint Publication 3-0, Joint Operations, V-1 to V-20 and VI-1 to VI-4.
2. Millett, et. al., For the Common Defense.
3. Snow & Drew, From Lexington to Baghdad and Beyond.
4. Stenberg, “The Failure of Polk's Mexican War Intrigue of 1845.”
5. Carney, “Gateway South: the Campaign for Monterrey.”
6. Snow & Drew, From Lexington to Baghdad and Beyond.
7. Stenberg, “The Failure of Polk's Mexican War Intrigue of 1845.”
8. Snow & Drew, From Lexington to Baghdad and Beyond.
9. Gaudi, African Kaiser.
10. Snow & Drew, From Lexington to Baghdad and Beyond includes a discussion of why neutrality is not in general possible. This warrants a one-word response: Switzerland.
11. Bridgeland, Outrage at Sea.
12. Millett, et. al., For the Common Defense.
13. Ibid.
14. It is not clear whether “grey zone” activities could be included in the continuum. See Robinson, “The Missing, Irregular Half of Great Power Competition.”
15. Joint Publication 3-0, Joint Operations, V-7 to V-11.
16. Ibid, V-12 to V-14.
17. Ibid, V-2 to V-4 and V-4 to V-5.
18. UTA Libraries, “Winfield Scott.”
19. Patenaude, "A Race against Anarchy.”
20. Stenberg, “The Failure of Polk's Mexican War Intrigue of 1845.”

Bibliography

Bridgeland, T. Outrage at Sea: Naval Atrocities in the First World War. Pen and Sword Books, 2002.

Carney, S. “Gateway South: the Campaign for Monterrey.” U.S. Army Campaigns of the Mexican War. Retrieved 25 June 2024 from https://history.army.mil/brochures/the%20campaign%20for%20monterrey/the%20campaign%20for%20monterrey.htm

Gaudi, R. African Kaiser: General Paul von Lettow-Vorbeck and the Great War in Africa, 1914-1918. Dutton Caliber, 2017.

Joint Chiefs of Staff. Joint Publication 3-0, Joint Operations, 22 October 2018.

Millett, A. R., Maslowski, P., & Feis, W. B. For the Common Defense: A Military History of the Unites States from 1607 to 2012. 3rd ed. Free Press, 2012.

Patenaude, B. "A Race against Anarchy: Even after the Great War ended, famine and chaos threatened Europe. Herbert Hoover rescued the continent, reviving trade, rebuilding infrastructure, and restoring economic order, holding a budding Bolshevism in check." Hoover Digest 2, 2020, pp. 183-200. Retrieved 25 June 2024 from https://www.hoover.org/research/race-against-anarchy

Robinson, E. “The Missing, Irregular Half of Great Power Competition.” Modern War Institute at West Point, 8 September 2020. Retrieved 25 June 2024 from https://mwi.westpoint.edu/the-missing-irregular-half-of-great-power-competition/

Snow, D. & Drew, D. From Lexington to Baghdad and Beyond: War and Politics in the American Experience. 3rd ed. Routledge, 2009.

Stenberg, R. “The Failure of Polk's Mexican War Intrigue of 1845.” Pacific Historical Review, Vol. 4, No. 1, March 1935, pp. 39-68. https://doi.org/10.2307/3633243

UTA Libraries. “Winfield Scott.” A Continent Divided: The U.S. – Mexico War. N/D. Retrieved 25 June 2024 from https://libraries.uta.edu/usmexicowar/node/4877