> The Euros also underfunded their defense obligations and received huge amounts of US investment in facilities, enabling them to upfund social programs, socialized healthcare and most egregiously 8 - 12 week vacations which are completely unheard of in the US.

It's hard to detect sarcasm through the screen but in case you're being serious and just repeat what Trump says, he does this because Americans are not stupid and are asking, why Europeans can enjoy free healthcare, education and 4-week holidays and we cant? The answer "because we sponsored them" makes no sense but finds fertile ground in the hearts of some people.