Somehow, I doubt the collection of fewer taxes will stop things like war. Instead, it's really you, me, and other taxpayers who aren't getting our cut.
This is a donation to a non profit. I think under the typical allocation of government "revenue", at least 40% of the taxes withdrawn from the donation would be used to pay for the war.
Tax rates aren't likely to change in response to how much is actually spent, as your comment seems to assume.
