From the Washington Post:
Fitzgerald has looked closely not only at the possible crimes, but also the context in which they would have been committed. This search, say lawyers in the case, has provided him a rare, glimpse into the White House effort to justify the Iraq war and rebut its critics.
The trail has often led to Cheney's office, which officials describe as ground zero in the effort to promote, execute and defend the Iraq war and the campaign to convince Americans and the world that Saddam Hussein had amassed a stockpile of the most dangerous kinds of weapons. According to the report in yesterday's Times, the investigation also led to Cheney himself.