It's in the financial interests of the US to be involved on the international stage. I listened to Trump's speech today and heard nothing but "Boohoo, it's so hard to be America". The reality is that the US is the gorilla in every room - we have the largest economy, largest military, and American hegemony has been a massive benefit to the country. Countries bend over backwards to gain access to US markets and millions still aspire to move here looking for better opportunities.
The whole situation reminds me of a quote from Interstellar - "We used to look up at the sky and wonder at our place in the stars. Now we just look down and worry about our place in the dirt."
We've giving up our global leadership for the sake of a few extra dollars in our pocket now - never mind the cost of inaction or every bit of scientific evidence that tells us something must be done. Even the Department of Defense believes that climate change is real and will have significant consequences for the US.
When did American exceptionalism turn into "It's too hard so I'm going to do nothing"?