I'm sure collusion is strictly outlawed by FIFA, but boy, would this ever be the right time for it. Germany is obviously not particularly scared of the US, but a draw not only puts them through to the knockout round (something that's not guaranteed if they lose to the US), it puts them through as the 1st place finisher of the group. So basically, they give up nothing by agreeing not to try to win (because a draw accomplishes the same 1st place finish), and gain immunity from the only thing that could knock them out by getting the US to agree not to try to win.
The US actually has something to lose by agreeing to tie instead of playing to win (a win would guarantee 1st, a tie would guarantee 2nd), and Klinsmann actually mentioned that when asked about collusion. But I guarantee they'd rather take their chances in a knockout game with Belgium (their next opponent if they finish in 2nd) than one with Germany right now.
