Maybe if the UN would do its job, there would be more of an incentive for the US to rely on the UN. The truth is that the UN, whose primary function is to facilitate peace, has been more of an impediment to peace in recent years than a facilitator. It failed to engineer peace between the Palestinians and the Israelis. It failed to engineer peace in Afghanistan, Iraq, and between Pakistan and India. It failed in Bosnia. It failed in Russia.
Why should the US bet the farm on a failed institution like the UN?
In the case of the Pallies and the Israelis I think it is much worse. The UN has sustained, even perpetuated, the conflict by setting up and maintaining 'refugee camps', refugee camps that have been in existence for over fifty years now (okay, I'll be generous, since the Six Day War, thirty seven years). Where else in the world do you see 'refugee camps' with high rise apartment buildings and all the aspects of cities? All so the UN can continue skimming money.
You wrote:
"It failed to engineer peace between the Palestinians and the Israelis. It failed to engineer peace in Afghanistan, Iraq, and between Pakistan and India. It failed in Bosnia. It failed in Russia.
Why should the US bet the farm on a failed institution like the UN?"
We shouldn't. It makes no difference to anyone on the left whether their policies produce a positive result. It is the policy that matters; not the results. They do not apologize for their failures and why should they? Their whole philosophy is one of failure. If they fail, no one has been elevated to success which (suits them just fine). Liberalism is a mental disorder.