When did the us policy of isolation end?

When the US declared war on Germany and joined the First World War. That was the first time the US Army was send abroad for any reason other than self-defense of the national borders.When did the us policy of isolation end?
Right after Bill Clinton didn't do anything while we were being attacked. He is the reason that we are in this war with terriorist (not the Iraq war). It didn't start with 9/11. We were attacked many times while he was in office. The terriorist found out that we were weak while he was in office.When did the us policy of isolation end?
Our isolation ended with Teddy Roosevelt. first after the French failed miserbly in building the Panama Canal, he got a war started in Columbia to get the Itmus of Panama to break off from Columbia and form its own government that was a proxy of the U.S. Teddy then finished what the French started with the stipulation that the canal was U.S. property. Lets not forget THe Spanish American war in Cuba that was really started by yellow journalism. Then the real kicker was his (teddy's) decision to sail the U.S. Navy Dreadnought fleet around the world to show the world that we were ready to kick *** and take names. He called that walking softly but carring a big stick. From that point on America lost its isolation from the world.
When the Japanese bombed Pearl Harbor.