Just because a place doesn't resemble Canada or Ukraine or people who look and act like your version of civilized society doesn't give the US a right to wage war resulting in large numbers of civilians being displaced or killed.
What's happening in Ukraine is reprehensible - but the result of US policy blunders in places like Afghanistan, Iraq, Iran, numerous South American countries and the like has been more damaging for the world we live in IMO.
While this isn't an apples to apples comparison, maybe you've got to convince us that the people of Iraq, Afghanistan, Iran, etc. are better off after US involvement. From my perspective, the answer is an obvious 'no'. Even under Saddam Hussein (who was a dictator and evil person - I'm in agreement there) the people of Iraq, who lived under some repression in their daily lives, were better off than before the US invasion.
Not commenting on the morality of the leak but given the IRS has been gutted [0] over the years by those in power, perhaps this insider was sick of seeing the public narrative on taxes be completely different from what was happening privately.
Unfortunately this is more the norm than the exception.
On a tangent, something similar happened with a Canadian Charity called WE [1] and them being chosen to run a billion dollar grant program for Canadian students during covid. It later came out that the charity had paid speaking/appearance fees to the PM's family as well as to the finance minister at the time. After enough outcry from the media + opposition + people, the finance minister resigned and WE was stripped of the contract.