That assumes that being a pacifist when living under the umbrella of the most powerful military in the world is, in fact, a virtue.

I don't think so. In order to be virtuous, one should have some skin in the game. I would respect dedicated pacifists in Kyiv a lot more. I wouldn't agree with them, but at least they would be ready to face pretty stark consequences of their philosophical belief.

Living in the Silicon Valley and proclaiming yourself virtuous pacifist comes at negligible personal cost.

That's kind of like saying that not being a murderer only has moral value if you're constantly under mortal threat yourself.

I don't really see the comparison. Not being a murderer isn't a virtue, it is just normal behavior for 99,9 per cent of the population.

First of all no one declared themselves a virtuous pacifist.

People don't participate in murder and they think others shouldn't either.

People don't participate in wars (which are essentially large scale murder) and they think others shouldn't.

Murder happens anyway. War happens anyway.

Yet if someone says 'war bad' people jump and say 'virtue signaling', but no one does that when people say 'murder bad'.

There's some really weird moral entanglement happening in the minds of people that are so eager to call out virtue signaling.

Virtue isn't childish, shooting telegraphed signals to be perceived as virtuous regardless of your true nature is childish. Also, using a one dimensional, stereotypical storybook definition of virtue (and then trying to foist that on others) is also childish.