The United States went to war with Mexico in 1846 in what is known as the Mexican-American War. I will share both sides of the issue regarding whether the United States was justified in going to war with Mexico. Then, you will be able to make an informed choice.

There were people who believed we were justified in going to war with Mexico. There was a border dispute between the United States and Mexico over the border with Texas. We said the border was at the Rio Grande River, and Mexico said it was at the Nueces River. When we went to negotiate with Mexico, they refused to meet with us. Thus, when the Mexicans attacked our troops that were in the disputed territory, we went to war against Mexico.

The United States was also looking for a way to expand to the Pacific Ocean. We believed it was our duty to expand to the Pacific Ocean. This was part of a general plan our expansion known as Manifest Destiny. We believed we had a responsibility to bring our way of life and our progress and improvement in general to the lands in western part of what is now the United States.

There are people who believed we weren’t justified in going to war with Mexico. These people believed it was wrong to manufacture a war in order for us to spread our way of life to areas by the Pacific Ocean. They believed the concept of Manifest Destiny was a concept that put down other cultures and ways of living. These people didn’t subscribe to the feeling that it was acceptable for us to push our ways onto other people.

Those who believed we weren’t justified in going to war with Mexico believed we provoked the Mexicans by moving our troops into the disputed territory. They believed this was a provocative action toward Mexico that left Mexico with little choice but to attack us. These people believed we could have worked harder at reaching a peaceful solution with Mexico.

Now that you have ideas on both sides of the issue, do you believe we were justified in going to war against Mexico in 1846?

Was the Mexican War justified?

The answer to this depends largely on whose ethical standards you apply.  To us today, this war was utterly unjustified and our country would never embark upon such a war today.  However, by the standards of its time, this war was much more justifiable. 

Today, we are very concerned with the idea that there must be a noble purpose to our wars.  We go to war to make the world safe for democracy or to prevent the spread of communism or to end terrorism.  By these standards, there was no reason to go to war with Mexico.  Mexico posed no threat to the United States.  It did not have an evil ideology that it was hoping to spread.  There was no noble cause and no serious issue of self-defense.  Therefore, we would clearly say today that this war was not justified.

In times past, however, the idea of a war to take territory and to make one’s country stronger was much more acceptable than it is today.  The idea of Manifest Destiny made it clear that the United States deserved the territory more than Mexico did.  Taking the territory would make the US more powerful as well.  With these sorts of justifications in hand, it was acceptable to use things like the snub of Slidell and the attack on American forces in the disputed area between the Rio Grande and the Nueces River as pretexts for war.

Thus, this war was perfectly justified when it happened, but it would be seen as a horribly unjust war today.