And Google, now a defense contractor willing to work on weapons of war to make a (bigger) profit, will gladly assist them.
They're themselves creating the incentive to do that, just as when they got into the content and content licensing game, they ended up creating the most aggressive content censorship system on the (free) internet, beyond even what the laws require. It's no longer a matter of "choosing to do the right thing". The (bad) incentives are already in place. Now Google just reacts to the incentives it created.
We're also supposed to "just trust them" that their secret AI Ethical Board, which can be replaced at any moment, also in secret, will do the right thing when things will go bad with its AI. They've already created the incentive to cheat by keeping that board secret.