The stance held by Google engineers seems to be more subtle than that, although it is fairly clear: a weapon produced by an American company may go either to kill a civilian in a pointless war in a country nobody has ever heard of (high-probability), or to kill a Chinese soldier in a future war for the survival of our country (low-probability). The US government could address this by improving the mix ratio between pointless wars that benefit nobody and wars for the survival of our country, so that a weapon would be more likely to end up used for the latter than the former.
Sure, but it is defensible that a greater balance of power might be a net good for the world. (Also the devil is in defining net good). And it is also quite defensible to restrict hard power to ethical channels. There's a reason we don't use chemical weapons even though they would definitely give us an edge: The moral harm outweighs the tactical benefit. (Until it doesn't, as we saw in Syria.)
I don't want a balance of power. I want most moral actor (however flawed they may be) to have a technical and tactical advantage over those that would behave immorally.
The world didn't get together and unanimously decide to stop using chemical weapons. The few strongest forces in the world decided that no one was to use chemical weapons, and by that threat of force the world became a better place.
Exactly, I don't see how setting up another cold war for the sake of proportionality will be good for the world. In the cold war nations still engaged in brutal proxy wars, and everyone lived in fear of a massive hot war. Doesn't seem preferable or more stable.
I would consider that an indefensible position.