Sometimes the motivation is foreign jealousy and malice. Sometimes it's American selfishness. Always it's naivete and short-sightedness.
I often think that it would serve Europeans and other foreigners who complain about right if Trump or some such crazy were elected and they got to find out what the world would be like without the United States taking its responsibility as the world's leading power seriously. But the mood passes.The next time a Hitler arises or famine or some natural disaster arises, we'll help again. It's what we do. It's who we are. To be the biggest kid on the block is to be hated- and we're big enough to bear that burden for the sake of the very people who so much enjoy hating us.
Afterward, the rest of the world can go back to being ungrateful.
Here's an outstanding documentary on what the world would really be like if America did withdraw from the world. Not that it will convince anybody.
After all, you can't reason people out of what they were never reasoned into in the first place.
The world will go on being ungrateful. And we'll continue bailing it out.