Answer:
Mexican view point, the war was not a result of greed or arrogance but a consequence to defend Mexico's territory from U.S invasion. And thus, the Mexicans would call this war as “The U.S War against Mexico”. During the 1840s, many Americans had the idea of a “manifest destiny” craved into their heads.
In 1845 the U.S. annexed the Republic of Texas, which had won de facto independence from Mexico in the Texas Revolution (1835–36). When U.S. diplomatic efforts to establish agreement on the Texas-Mexico border and to purchase Mexico's California and New Mexico territories failed, expansionist U.S. Pres. James K.