He slithered his way into being Bush's VP, then controlled shit behind the scenes. GWB has commented something along the lines of Cheney ruined his legacy. Cheney was connected in DC and lots of people in Bush admin we're actually Cheney associates. Cheney was also connected to GHWB, which means he's a friend of the CIA.

Through all those connections, it's broadly speculated that Iraq invasion was always his plan even before taking office. Most VPs don't have much public profile but he was on TV lying to America about Iraq and Afghanistan

Cheney and his oil baron cronies profited off the wars.

Cheney publicly defended torturing prisoners in Gitmo and Abu Graibh

Cheney assumed control of the US government from a bunker on 9/11 (IIRC?)

Usually I don't say his about VPs but I Cheney is as much a war criminal as anybody else in the Bush administration