Under Trump, he said, America could no longer be relied on.

This should be “with a population that supports and enables a kleptocratic dictatorship, America could no longer be relied on.”

This isn’t just Trump. It’s American conservatives, the whole political class, corporations, and civilian population that are ultimately to blame for this mess (in that order). Anything less than a civil war won’t result in the threat being neutralised for decades, and will define the rest of 21st Century geopolitics.

I see this as being the thing creating an EU like military.

A joint military deterrent is going to be expensive and would not be trusted to one country like it was with the USA. That is going to create a military command which has the authority to raise money and decide when to deploy nuclear weapons. I doubt this would be trusted to a non-EU agency.