Probably for the same reason our country flushed trillions down the toilet of Johnson's "Great Society" programs--because it could be done, not because it was wise.
Are you suggesting the Sweden give up the military that kept it protected from the Nazis and Soviets? Have oyu been paying attention to Putin? Who do you think would come to the aid of our Nato allies in Estonia, Latvia and Lithuania when Putin whips Russian irredentism and revanchism to invade? Do you think Obama will?