shootin,
That's not an "apples to apples", and criminalizing politics (not warfare) is wrong no matter who does it.
What the VT prosecutor is talking about is charging Bush, not for his command decisions during the war, but for her view of his decision-making process leading up to it.
War crimes under international law cover actions taken during a war, they don't weigh in on the rational involved in making the decision to go to war.
By definition, the war was legitimate (setting aside subjective right and wrong) as it was voted on in Congress and was justified under any number of violated UN resolutions, acknowledged at the time by the Security Council, completely separate from the claimed connections to 9/11 or fears of WMD.
The only people who can legitimately protest about any claimed lies in getting their authorization is Congress itself via the impeachment process, or teh Security Council under theirs, both of which have declined to do so.
So, we aren't talking about criminalizing warfare, but rather criminalizing decisions the political opposition disagrees with, after they come into power, after a legal handover of said power.
That cannot happen and preserve the Republic.