Leaving zero troops in Afghanistan? It's a serious option, Pentagon says.

Following through on the so-called “zero option” for Afghanistan – in which no US troops would remain in the country past 2014 – would be a dangerous way forward for the Pentagon, warn some lawmakers who say they are increasingly concerned about the prospect.

Yet US officials nonetheless continue to use the threat of such a move in an effort to gain leverage over Afghan officials who refuse to grant US forces the legal immunities that the Pentagon insists they need to remain in the country, adds Sen. John McCain (R) of Arizona.

This, in turn, is having “a very significant damaging effect” on the ground, he added, while charging the White House and Pentagon officials with sending mixed messages to Afghanistan. “You never point a loaded weapon at somebody unless you are ready to pull the trigger.”

The former ambassador to Afghanistan, Ryan Crocker, weighed in with his own blunt assessment of the “zero option,” too: “If it’s a tactic, it’s mindless; if it’s a strategy, it is criminal.” 

In the hopes of pressuring Pentagon officials to give their unvarnished views of the advisability of a “zero option” – along with several other key aspects of the Afghanistan campaign – Senator McCain, along with Sen. Carl Levin (D) of Michigan, chairman of the Senate Armed Services Committee, this week sent a list of five written questions to be answered by the nation’s top military adviser. 

These include, for starters, asking Gen. Martin Dempsey, chairman of the Joint Chiefs of Staff, whether he believes that the US military is winning the war and whether America has “national security interests in Afghanistan that justify an enduring presence of US forces beyond 2014.”

Other questions were more politically pointed. To wit, “Do you believe it is appropriate to accept the risk of drawing down half of our combat force in Afghanistan by February or March of next year, just a few weeks before the country’s presidential election?”

President Obama has already ordered the Pentagon to draw down US troops throughout the country from 63,000 currently to some 34,000 by February of next year.

Even as the political wrangling continued on Capitol Hill, General Dempsey traveled to Kabul this week to meet with Afghan President Hamid Karzai.

While he was there, he shed some behind-the-scenes light on the Pentagon’s planning surrounding “zero option.” 

In short, there is none, he told a reporter who asked just how serious the US military is about the “zero option” during a press conference.

“Now that’s a great question,” Dempsey answered

He continued, “Well, first, I don’t have a zero option. No one has asked me to prepare a zero option. I don’t recommend a zero option.”

That said, he did note, in a pointed remark aimed at Afghan politicians, that “there could be a zero outcome, because we can only stay here if we’re invited to do so.” 

He was referring to a bilateral security agreement that has yet to be brokered, which includes the highly charged topic of legal immunity for US troops. 

After his meeting with President Karzai, Dempsey said, “I’m somewhat more optimistic than I was before I came over here that we can work through this.”

In the event that effort should stall, however, Pentagon Press Secretary George Little turned up the heat. 

“If the plan is for zero [troops]," he said, “that’s a relatively easy plan to develop.”

While putting such a plan together may be "easy," military logistics specialists eyeing millions of rounds of ammunition, crates of gear, and the prospect of cargo planes full of trucks bound for a return flight back to the US might argue, however, that following through on such a threat is another matter altogether.