One, Obamacare doesn't work. Two, legitimate functions of a government are not socialism. Police, fire, roads, military, taxes to support them are not socialism. They are what we pay a government to do because we cannot do them successfully as individuals. You really should go read up on socialism.
Right, like Britain didn't until they were attacked, real smart of them.
As to the US being in Isolation, perhaps you should look up whaling. The discovery and adoption of petroleum products. The Spanish American War. The invasion of Tripoli and suppression of the Barbary Coast pirates. The voyages of Commodore Mathew Parry. The Korean Expedition, in 1871. The Monroe Doctrine. etc, etc.
If we take action against someone, even economic sanctions, then yes, we are part of the war. Active war is only one method of pursuing our National Goals and Strategies. In economics we have conflicts with other nations. Without the use of military force, we cannot protect shipping and international markets which we depend upon. And finally, it is always better to fight a war on someone else's land than your own. Much easier on our civilians that way.