A summary of the group's concerns:

1. Conditioning U.S. withdrawal on the "We'll stand down when they stand up" formula: They'll more likely stand up when we stand down. The continued presence of U.S. troops provides little motivation for Iraq's security forces to assert themselves.
   
2. Placing too much focus on Iraq's central government: The central government of Iraq is a fiction. Iraq's leaders disagree on the country's future direction and the country's political parties are bitterly divided along religious and sectarian lines. These divides may ultimately prove unbridgeable.
   
3. Paying insufficient attention to the Iraqi Constitution and the will of the Iraqi people: The ISG report calls for the central government to control Iraq's oil revenues, contrary to the wishes of the Iraqis themselves, who voted for decentralization. In addition, most Iraqis want U.S. forces to leave within a year and a sizeable majority (61%, according to one poll) support attacks against Americans.
   
4. Supporting the unconditional training of Iraq's security forces: The ISG report recommends a force of between 10,000 and 20,000 U.S. military advisors to train Iraqi troops, but advisors would require large numbers of additional U.S. troops for force protection, removing them from other key positions around the world. In addition, the Iraqi army continues to be unreliable and overridden by sectarian divisions. Loyalties to tribe and religious sect override loyalty to the state.
   
5. Offering undeveloped ideas on a regional diplomatic offensive: The ISG recommends the creation of a regional contact group to solve Iraq's internal and external problems diplomatically. Such a "one-size-fits-all" approach fails to recognize the individual concerns and differing interests of each of Iraq's neighbors.
   

Whether the Democrats will listen to these concerns remains an open question. If the amendment were to pass, it would (despite its flaws) be the toughest challenge yet to the Bush administration's approach to Iraq. But it might be too little of a good thing, especially for angry Democratic voters.