> unfortunate for Ukraine, but it's not necessarily their problem
It seems like it absolutely is the US's problem, albeit indirectly. If Russia gets the outcome it wants in Ukraine, they'll have access to rich mineral deposits, vast quantities of grain, and nuclear power, boosting their economy and their status as a rival world power to the US. It will signal to Putin that he can be aggressive towards other neighbouring countries with little pushback. The war has resulted in a growing alliance between Russia, Iran and North Korea which is altering global military power dynamics and not in the US's favour. Also, China is watching what's happening with eagle eyes to determine whether to invade Taiwan, which would definitely escalate the US's engagement.
It seems like it absolutely is the US's problem, albeit indirectly. If Russia gets the outcome it wants in Ukraine, they'll have access to rich mineral deposits, vast quantities of grain, and nuclear power, boosting their economy and their status as a rival world power to the US. It will signal to Putin that he can be aggressive towards other neighbouring countries with little pushback. The war has resulted in a growing alliance between Russia, Iran and North Korea which is altering global military power dynamics and not in the US's favour. Also, China is watching what's happening with eagle eyes to determine whether to invade Taiwan, which would definitely escalate the US's engagement.