That is not the relevant question here. The relevant question is whether we can think of acts that are so incompatible with the "national character" that it would be inconceivable (i.e. p~0 can be assumed for all practical purposes) that any institutions of a given country's government would commit them, although such acts have been committed by governments in other places and times. The answer is obviously yes.

I can think of only such acts as wouldn't benefit such governments in question. E.g. it wouldn't benefit the US government to cook alive suspected terrorists and use their flesh to feed its troops. Cannibalism isn't part of the American national character -- and it doesn't benefit the US government either, so it doesn't do it.

But I can't think of any acts that would be effectively impossible to be committed by an institution of any government though it would benefit it, merely because it's "not in the national character" to do so. If something is not in the national character, then said institution merely does it in secret.