Ronald E. Neumann was U.S. ambassador to Afghanistan from 2005 to 2007 and is the author of “The Other War: Winning and Losing in Afghanistan.”

Defense Secretary Leon Panetta provoked a widespread misunderstanding this month when he spoke of the U.S. military’s changing mission in Afghanistan, to that of an advisory role. Media reports of Panetta’s comments indicated that this meant U.S. forces would speed up their withdrawal from that country, when the White House has yet to make any such decision and the basic strategy of transition is unchanged.

Compounding the confusion is the public’s misunderstanding of the current policy in Afghanistan — of transferring the “security lead” to the Afghans at the end of 2014 — the basic strategy of which remains unchanged.

This transfer is not a timetable for the withdrawal of all foreign troops. Rather, the policy is that, after 2014, the Afghans will do the bulk of the fighting but will still have advisers from abroad in combat with them. U.S. forces are still expected to supply air support, artillery, medical evacuation and combat logistics after 2014 because the Afghan army will have none of these support services ready before 2016 at the earliest. The U.S. role will shift, but it is critically important to understand that, in the shift to a mission mainly devoted to advising and supporting — whatever the terms used — our forces will still be fighting on the ground, before, during and after 2014.

Panetta made this explicit Feb. 4, saying at the Munich Security Conference that, after 2014, “we will engage in combat alongside the Afghans as necessary.”

Thus the United States and its coalition allies face two big issues. The first, which Panetta focused on, is how to transition successfully to Afghans having the security lead. The second involves securing Afghanistan after the transition.

While the NATO-led International Security Assistance Force (ISAF) has achieved considerable success in southern Afghanistan, this is not true in the country’s east. There, security has declined: Insurgents have gained control in some areas, and an ISAF offensive needs to precede any transition.

The transition strategy must be adaptable to these different situations. In some areas, the Afghans would lead, with U.S. advisers and with larger U.S. combat formations available to support as needed. In other areas, where tough clearing operations are required, the U.S. military would continue to lead for some time.

The gradual shifting of roles that Panetta referred to needs to begin well before 2014 because it is going to need fine-tuning along the way. U.S. officers will have to turn over responsibilities to Afghan forces that will not be at U.S. levels of proficiency — letting them have room for mistakes but supporting them when trouble arises. Afghan soldiers need to develop confidence that, when the chips are down, help will arrive. While Afghans need to be pushed to take more responsibility, failure is likely if the process is artificially rushed, with green troops required to take too much responsibility too soon.

Over the next three years, commanders will need the flexibility to judge not only where and when to transfer responsibility but where to reinforce with ISAF forces — to manage inevitable mistakes or to counter the enemy’s gains. These difficult judgments will require a flexible reserve force. This is why the Pentagon needs to retain for some time most, if not all, of the 68,000 U.S. troops in Afghanistan after the withdrawals scheduled for this year. Operational judgments need to be based on the fighting, not on an artificial timetable. The White House has not decided on troop numbers after 2012, but the strategy Panetta discussed will need to keep up the force numbers well beyond mid-2013 or else risk failure.

Public confusion arises not only from ill-considered words but because U.S. decisions need to be adopted by NATO, something that may not be achieved until the organization’s summit meeting in Chicago in May. This adds opacity to briefings since the policy cannot be fully declared in advance of buy-in by our allies.

They, and we, must address not only the forces needed throughout transition but also the second big issue — how to fiscally and militarily sustain a post-2014 Afghanistan. The United States must avoid cutting funding for the Afghan forces just at the moment of their greatest challenge. We need to define our intentions and commitments after 2014 because transition has to be toward a defined goal, not a cliff over which we tumble. Concluding the current negotiations for a strategic partnership may clarify our purpose — if the current stalemate does not lead to their breakdown.

The clarity and steadiness of our purpose will significantly affect whether Afghan forces focus on improving their capabilities or spend their time worrying about how to survive if we withdraw too soon. The strategy of transition asks our commanders for large measures of resolve, discipline and courage. They have every right to expect clarity and resolve from their political leaders. President Obama needs to explain his strategy to Americans, not talk only about withdrawal dates.