These employees are free to exercise their right to (not) work for whomever they want, but the certainty they express (as well as most commenters here) in their own self-righteousness seems misplaced to me. There's certainly a case to be made that a strong US military is in the world's best interest. In fact, I would wager that a majority of Americans (and a majority of citizens of democratic countries across the wor…
One point I haven't seen raised here is that "a strong military" is not a one-dimensional proposition. The military does a lot of things in a lot of contexts, and they don't all have the same moral value.
If someone wants to build better Humvee armor for the US Army, I wouldn't criticize them at all. I don't think there's a reasonable case that better-armored Humvees are worse for the world. (Not least because we proved in 2003 that a lack of proper armor doesn't deter the US from starting wars.)
But I think the work Google engineers are likely to do for the US military is not likely to advance Pax Americana, which is mostly about a nuclear umbrella and secure international shipping lanes. Instead, it's very likely to abet either the drone war or mass surveillance, since those are closer to Google's area of expertise.
Quite a lot of people who are not strictly against US superpower status are still deeply opposed to the specific sorts of action Google would be best-placed to enable. And since they haven't actually signed on with the military, it seems totally reasonable that they would object to doing such work even if they do value a strong US military in other domains.