Trump has started trade wars with Europe, China, Canada, Mexico, Asia ... and is in the process of openly pissing off everyone. You're rapidly running out of friends.
What friends to begin with?
Europe --- Maybe the UK and Poland at some point, but the UK is obsessed with its own problems and Poland is hostage to the EU. The EU has never been a friend of the USA. The USA helped it rebuild after world war 2 and payed for its defense for 70+ years. That's hardly friendship. NATO? No one in the USA has ever expected the EU to provide any meaningful support if the USA got into a major war with another super power. It's always been a one way agreement where the USA protected the EU from the USSR and that's it. Anyone who says otherwise is just repeating propaganda.
China -- has been saying internally that they planned to replace the USA as the leading superpower and its military has been preparing for conflict with the
USA for the last 10-20 years. It's also been stealing all the technology it can and looting American companies who want access to its consumer market. The population has become increasingly nationalistic and has always been somewhat xenophobic.
Canada -- I wouldn't say has ever been a friend, more of an easy going business contact next door.
Mexico -- No, never a friend, more like the neighbor next door that constantly needs help and sends you their problems. Yes, some of dreamed of NAFTA being the opening move towards a North American Union, like the EU -- But the cultures are just too different.
Asia -- Strangely enough, One could argue that we have had a real friendship with Japan, South Korea, Philippines, and modestly Australia. The last president destroyed the Philippines relationship. South Korea and Japan are good enough, but both are primarily interested in the USA protecting their independence from a militaristic China and North Korea and Trump has been doing what he can to maintain and build those relationships.
Basically, the existing world order is a result of Americans concentrating on sacrificing its own interests and building world wide prosperity in order to prevent a repeat of the two previous world wars. It's allowed the defeat of the USSR, and the rise of a new multipolar war with several prosperous economic-geographic regions (Asia, Europe, Russia, Middle East). The regions are eager to get the benefits of super power status while letting America continue to bear the overwhelming cost of maintaining a new world order that benefits them. Trump has said enough and asked to re-negotiate. Of course, negotiation is divisive....but ignoring the issues and throwing the can down the road will not improve matters either.