How did you think the world will turn with America under Trump?
My thoughts.
Ukraine.
Trump will try to do a deal with Putin ceding the eastern states of Ukraine to Russia. I think Putin has got his fingers burnt in Ukraine and despite fears this will embolden him to attack other countries, I don't think he will. Or at least not countries in Europe, Georgia (we can argue about whether that's in Europe or not) and some of the Stans might be under threat though. I think this will be more likely (successful) political interference from Russia than troops on the ground though. I think winning the eastern states will play as a big win for Putin in Russia and allow him to climb down. Zelenski will object, seek support from Europe, won't get it, and will be forced to accept and move into exile with a Russia price on his head.
Trump will portray this as a massive win and himself as the peacemaker.
This episode will embolden China and North Korea.
China will invade Taiwan, Trump won't give a shit and nobody else will put money or troops into defending Taiwan. Europe/Austrailia may impose some sanctions and strong words at the UN, but that'll be it.
North Korea may want or try to invade South Korea. I think North Korea is in a difficult position here though. If they were to invade South Korea and send troops across the border, well, that also pulls back the curtains. North Koreans get a proper view of the South and the lies and brainwashing of the North Korean leadership are exposed. So, don't really have any idea what will happen there.
Middle East
Trump will be wholeheartedly in support of Israel and willing to arm whatever action they take. Iran will also now be on their own as I think it will lose any support it may have had from Russia or China. Neither country really give a shit about Iran, it was just a 'my enemies enemy is my friend' situation. Militarily, America will no longer be Russia or China's enemy.
Europe again will have strong words but thats all.
I don't think Israel's military might will be enough to streamroller its enemies though, the terror and attacks against Israel and exported to the RoW will continue and grow. Israel may win a war with Iran though, in much the same way the West 'won' a war in Afghanistan. Can't see a path for real peace here.
As may be clear, I really no nothing about international relations so hopefully those better informed can put me right.