Tony Campolo (in his audio speech: Christianity after Sept.11) suggests that the ones urging caution are the ones with war experience with Iraq,  and the ones urging “pre-emptive strike” are the ones without. 

“Split over Iraq grows more public By John Diamond, USA TODAY WASHINGTON â014 A rift over Iraq has emerged among senior advisers in the Bush administration who helped wage the first Persian Gulf War and now face the possibility of a second. On one side are hard-liners such as Pentagon adviser Richard Perle and Deputy Defense Secretary Paul Wolfowitz. They urge the ouster of Iraqi leader Saddam Hussein now, with force if necessary. They say it’s too dangerous to wait until he has weapons of mass destruction pointed at the United States and its allies. On the other side are those such as Secretary of State Colin Powell and former national security adviser Brent Scowcroft, who advise caution and warn of the consequences of war.“