Europeans should spend more on defense. Defense is one of the budgetary requirements that should not get a cut back in regards to balancing the national debt. The defense of a nation is one of the major responsibilities of government to its people. European nations should spend more on defense.
There is no clear reason why Europe should spend more on defense than it currently is. There has not been a serious attack on a European country for many years, and there is no clear danger today that cannot be currently faced. The US spends a massive amount on defense because its taken upon itself the mantle of world military authority - something Europe has neither done nor desires to do.