Amidst rising criticism from Republican ranks and a deepening split with Iraqi leaders, Defense Secretary Donald Rumsfeld has issued a new message to critics of the Iraq war — “back off.” At a Pentagon briefing Thursday, Rumsfeld told reporters: “This is complicated stuff. It’s difficult. We’re looking out into the future. No one can predict the future with absolute certainty. So you ought to just back off, take a look at it, relax, [and] understand that it’s complicated… but it will get worked out,” he said. Rumsfeld’s comments come as increasing numbers of Republicans are calling for his dismissal. On Wednesday, Republican Senator Olympia Snowe of Maine said President Bush should have accepted Rumsfeld’s resignation when it was first offered. Republican Senator Mike DeWine of Ohio and Congressmember Anne Northup of Kentucky also called for Rumsfeld’s replacement this week. Northup said: “You cannot afford to lose the numbers we are losing now and just keep slugging away.”