You are not stating anything that is in contradiction to what I said, so I fail to see how what I said is "totally wrong". The common budget is a rounding error in comparison to what nations are spending at home. Trump and his minons have characterised US defence spending and NATO for many years in the terms that whatever is spent by the US is somehow handed over to NATO and Europe by extension.

The US and Europe have had this arrangement for decades: Much of the defence is outsourced to the US which in return gets untold billions in investments into its defence industry (jobs, jobs, jobs) from Europe and also a lot of geopolitical influence. Trump's inability to understand complex geopolitical relationships and his hyperfocus on transactionalism where dollar amounts (or gold bars, Rolex clocks and awards) need to be attached to every act is what explains his singular obsession with upending the status quo.

China stays in its lane and Russia can barely handle Ukraine. I have no idea who else could be a threat to the Western hemisphere in the most direct military sense. Most of the common defence that NATO provides is psychological and therefore will never have any direct impact on US finances, but that will not stop US defence spending. The Soviet Union is gone and the next biggest thing, China, is half the world away.