The U.S. did not play their game at all. The U.S. squad is one built on speed and finesse. They are best when playing an attacking style offense, especially the counter attack after defensive stops.
Today they tried to play a more controlled and slowed down game. The problem with that is they can't hang with bigger teams like the Czechs, they just get muscled off the ball.
Team USA looked lethargic and old, when in reality they are a pretty young squad that should have had many more shots on goal. They should be embarrassed, not for losing, but for their dreadful play today.
On a side note I think it's time for Bruce Arena to step down as the coach. If the U.S. wants to compete on the world stage they need to have as much international experience as possible, including inside the coaching ranks.