Senate Republicans on Tuesday looked to stiffen President Barack Obama’s resolve to carry out a major troop escalation in Afghanistan, as Democratic leaders moved to put on the brakes before thousands more U.S. troops are sent into combat.

Senate Majority Whip Dick Durbin (D-Ill.) said that at this point he would not support increasing troop levels and threw his weight behind Armed Services Chairman Carl Levin’s (D-Mich.) proposal to instead bolster Afghan troops and government infrastructure.

When asked if he supports sending in more troops, Durbin said: “No, I’ve joined Sen. Levin on this. His approach is a reasonable one. … We should not meet the needs of Afghanistan at the cost of more American lives.—

But Republicans pushed back against efforts by the administration and Congressional Democrats to take more time before committing to a troop increase.

“We know what Gen. McChrystal’s recommendation is. We read it in the Washington Post. We don’t understand the delay in the president acting on that recommendation,— Senate Minority Leader Mitch McConnell (R-Ky.) said.

The Washington Post on Monday released a leaked strategy plan prepared by Gen. Stanley McChrystal, the top commander in Afghanistan, that argued for an increase in troop levels as well as efforts to help build up the Afghan army and the country’s civil infrastructure. The leak caught the White House — which has sought to delay McChrystal’s troop level request temporarily — and Democrats off guard.

Obama has reportedly asked McChrystal to delay issuing his formal request for more troops while the White House studies his plan, and the president over the weekend said he would not make a final decision until he had a chance to conduct that review.

Armed Services ranking member John McCain (R-Ariz.) harshly criticized Democrats. “The strategy is already there. The question is, are you going to implement the strategy? It defies logic.—

Sen. Lindsey Graham (R-S.C.) said that while he supports increasing troop levels as soon as possible, he also backs much of Levin’s plan. Graham said his greatest concern is that Obama may bow to pressure from the progressive community to take up a counterterrorism, rather than a counterinsurgency, approach to Afghanistan. “A counterterrorism strategy is a recipe for disaster,— Graham said.

Graham and other Republicans declined to publicly question Obama’s motives in seeking a delay of the troop request. But privately Republicans worried that the administration has softened its approach to Afghanistan in recent weeks with an eye toward the ongoing health care debate. Several Republicans pointed out that Obama’s decision to delay the troop request came just as he was pressing liberals to accept health care reforms that do not include the kind of public option the left has long sought.

Given Obama’s tricky relationship with his left flank, “there’s going to be some angst among Republicans with how this thing is being played. He’s in a difficult position trying to keep his left wing happy while trying to give the commanders on the ground what they need,— said one GOP Senator who spoke on the condition of anonymity.

McCain, who declined to speculate on Obama’s motives, warned against using traditional Washington horse-trading tactics when it comes to Afghanistan. “You can’t just trade away American national security,— McCain said.

Sen. Joe Lieberman (ID-Conn.) said he hopes a decision will be forthcoming. “While I respect the president’s right to deliberate, I hope he’ll make a decision soon.—

But Durbin and other Democratic leaders appeared set on backing a significantly slower process. Durbin echoed recent comments by Vice President Joseph Biden indicating that no decision should be made on troop levels until after the results of the Aug. 20 elections are final, noting that President Hamid Karzai’s “legitimacy is at least on hold.—

Likewise, Senate Majority Leader Harry Reid (D-Nev.) called for a consultative process and warned that an agreement on troop increases may not come easily.

“The administration, of course, as they’ve indicated, needs to work with the Armed Services committees in the House and the Senate to coordinate what the next steps are,— Reid said, adding, “But as to when that happens, I think there are many questions that we need to have answered. That is, we need to have meaningful consultation with the administration, including our military leaders, on the decisions that are before us.—