I agree with much of what you just wrote.
At the end of WWII Europe was given safety guarantees called the US Nuclear Umbrella that did not require them to keep huge armies.
Although, during the Cold War most European nations did have significant armies but after the fall of the Soviet Union they quickly started to spent their money on more profitable subjects.
Then this criminal Putin came to power but heh, we have a NATO chapter 5 and like in WWII the US will come to our rescue, one of the reasons most countries did not invest in nuclear weapons.
But now along comes this unusual friend of Putin, Trump, and he wants to retreat to his side of the Atlantic.
Many but not all European nations realize they'll have to invest in and set up their own defense, just a pity not all see the need for rearmament and some like Viktor Orban look at Putin as a trading partner, Orban already gave up on an independent legal system and free press so the Russian system is not so different, right?