You can go way further than that. The US initially only declared war on Japan and not Germany, only to join the European Theatre later.

There are various interpretations of this, but it seems plain to me that they were hoping the Nazis would beat the Soviets and the US could decide what to do from there, but once the Soviets began to resist more effectively, the US needed to make sure that the Soviets wouldn't get control of the entirety of Germany's manufacturing capacity in the case that they won out*, so they joined in Europe to ensure the liberal coalition would control a portion of Germany.**

*Which most historians agree they would have, even without the US

**Which is indeed what happened