The question can be read two ways:
1) Under what conditions should the US commit genocide? -- The answer to this question is NEVER. Genocide, the extermination of a specific ethnic, racial, or religious group, is the worst crime as yet named by humanity and is not justified by any secular norms or conduct. There is a reason why nearly all countries (including the US) have signed conventions against genocide; it is an appalling crime.
2) Under what conditions should the US intervene to prevent genocides in other countries? -- This is a much more subjective question and one that is often very controversial, especially between isolationists (who oppose US intervention in foreign conflicts) and war-hawks (who recommend US intervention in foreign conflicts). However, stopping a genocide is the one case where isolationists are most willing to concede the value of some limited intervention, often to protect the fleeing victims of genocide or grant them some kind of asylum. War-Hawks often argue that direct intervention is necessary in order to end the genocide and bring the responsible parties to justice. While isolationists may concede that this is a noble goal, they will often argue that (1) it is not worth the blood and treasure of the US to achieve this goal or (2) that there is no guarantee that the post-intervention environment will be better than the pre-intervention environment.
The US should have definitely got involved in the genocide because there were mass murders and they could have done something.
Because the US already has a big debt to pay and cannot afford another war/"intervention"
No, but we should be kind to foreigners and we should be willing to help them when they ask!
Ever since they labeled it as a genocide they have been saying they are going to help yet so far verry little has been done to help the citizens in darfur
which genocide?
'55.
Vietnam.
Every nation, including the United States, should do whatever is possible to prevent genocide. Genocide is the greatest crime against our common humanity and as civilized people around the world, we must unite on this one question of the value of life.
The U.S. became involved after the bombing of Pearl Harbor.
1964-1975
The United States should care about honoring the suffering of people who were butchered for who they were and what they believed, especially since the United States is a country founded by people who fled the Old World specifically because of ethnic and religious persecution -- just like what the Armenian, Pontic Greek, and Assyrian people suffered in the Ottoman-led genocide.Additionally, US Recognition of the genocide may force Turkey to become more introspective about its consistent denial of this unfathomable crime. To read more about the Turkish stance on the Armenian Genocide, please see this Related Question: Why does the Turkish government deny that a genocide took place?
The sinking of the Lusitania caused the US to get involved.