The interesting question is, who wins the primary? And what happens in it?
Could the Democrats be forced into some extreme anti war stances? - something like "never never never" that isn't walked back in the general (because how and why).
This might make involvement impossible, especially since he would still have re-election to work on.
On the other hand, without incumbency maybe the Republicans win (who may or may not go for the same guy), and the Germans become more cautious and ironically thus never let's the Republicans get a valid CB?