The United States in 1846 was not justified in going to war with Mexico. The United States did not have proper justification to respond with violence against the Mexican government. The war with Mexico was also a product of the United States' belief of manifest destiny. Polk's over ambition to seize new territory from the Mexicans and disappointment over their refusal to sell him California also possibly played a factor in his willingness to wage war …showed first 75 words of 829 total…

…showed last 75 words of 829 total…with fulfilling campaign promises and greed for new land. Also Polk was looking for revenge for the denial of the proposal for buying California as was evident in his original reasons for declaring war on Mexico. Also the US provoked this boarder dispute into the two-year war that it became by purposely inciting the Mexicans into a fight. All these reasons are the evidence that the US was not justified in declaring war on Mexico.