"In the absence of enemy tanks at the border, many nations in Europe are happy to let the military budgets subside, even without the economic malaise. U.S. defense secretary Robert Gates summed it up neatly earlier this year. "The demilitarization of Europe?where large swaths of the general public and political class are averse to military force and the risks that go with it?has gone from a blessing in the 20th century to an impediment to achieving real security and lasting peace in the 21st," he said during a speech. "Since the end of the Cold War, NATO and national defense budgets have fallen consistently, even with unprecedented operations outside NATO's territory over the past five years."
As for the lack of European military that the USA is whining about:
Including reserves we have:
6.8 million personnel 6,800 main battle tanks 3,500 combat aircraft 1300 transport aircraft 7 aircraft carriers [And about 600 nuclear warheads between Britain and France]The real complaint seems to be that we have had enough of fighting US wars.