Does it need to? My guess is that the US starts its own league and doesn't give a damn what the rest of the world thinks.
Hard to compete in the World Cup when your leagues play a significantly different version (which cutting 1/3rd of the playing time would be) of the sport to the rest of the world and isn't under the FIFA umbrella.
Either you'd have made the conscious decision to pull out of the World Cup and other internationals, be relying on American players in foreign leagues for your national team, or using players that are used to competing in a different format and at a disadvantage.
But ooh rah, American exceptionalism.