The Mexican-American War was not justified. This conflict, which lasted from 1846 to 1848, was a result of territorial disputes between Mexico and the United States. While some argue that the U.S. had legitimate reasons for going to war, the evidence suggests otherwise.
Firstly, the dispute over Texas was a major catalyst for the war. Texas had declared its independence from Mexico in 1836, but Mexico still considered it a rebellious province. When the United States annexed Texas in 1845, it exacerbated tensions between the two nations. However, the annexation itself was unjustified as it violated the principles of self-determination and territorial integrity.
Furthermore, the United States had a manifest destiny mindset, believing it was their destiny to expand westward. This belief, combined with economic motives, fueled the desire to acquire Mexican territory. As President James K. Polk stated in his message to Congress, "Mexico has passed the boundary of the United States, has invaded our territory and shed American blood upon the American soil." However, this claim was disputed, and the U.S. was widely seen as the aggressor in the conflict.
Additionally, the United States used questionable tactics during the war. The American army under General Zachary Taylor provoked the Mexicans into firing the first shots, giving the U.S. a pretext for military action. The U.S. also notably invaded Mexico City, which was a clear violation of Mexican sovereignty.
In conclusion, the Mexican-American War was not justified. The conflict was rooted in the United States' desire for territorial expansion and economic gain. The U.S. annexation of Texas and the questionable tactics used during the war further highlight the unjust nature of the conflict. This war serves as a prime example of imperialism and aggression, rather than a justifiable endeavor.