The Trump administration has made numerous foreign policy errors but when it comes to nuclear proliferation there is plenty of blame to go around. The Budapest Memorandum was signed under the Clinton administration, and it specifically didn't require the USA to defend Ukraine. Russia first invaded Ukraine in 2014 and the Obama administration didn't do much about it (and other EU/NATO countries also did effectively nothing). Russia then re-invaded Ukraine in 2022 and the Biden administration provided a little support but still the Ukrainians were largely left to fend for themselves. I'd like to see the Trump administration do more (short of direct military involvement) but still this is primarily a European issue. Why have the other European countries been so lazy and passive instead of asking their citizens to accept the risks and sacrifices necessary to defeat Russian aggression?

We'll probably see more nuclear proliferation going forward, regardless of who sits in the White House. No way to stop it now.