I was just going to say almost exactly this: it might be worth reading Richard Rhodes' The Making of the Atomic Bomb, in which he points out how many of the essential scientists and engineers working in aspects of the Manhattan Project were Europeans. Some of the most essential figures, like Leo Szliard (sp?), were.

I dare say a handful of physicists and chemists did not have major bearing on the US economy, after their accomplishment of needlessly incinerating a bunch of japanese.

He's "merely" forgetting that von Neumann, von Karman, and Andy Grove all came from Hungary.