FIVE MONTHS ago, President Trump abruptly aborted plans to conclude a deal with the Afghan Taliban, citing an attack that had killed a U.S. soldier. Now the accord is back, with one addition: a seven-day period beginning Saturday in which both the Taliban and U.S. forces are to refrain from major offensive actions. If the partial truce holds, Secretary of State Mike Pompeo said Friday, the deal will be signed Feb. 29, and intra-Afghan negotiations will begin soon after on “a comprehensive and permanent ceasefire and the future political roadmap for Afghanistan.” Meanwhile, a drawdown of U.S. troops will begin.

Present and certain former U.S. officials are describing this as the best chance for peace in many years. We hope that’s the case, but the deal is difficult to judge because many of its terms remain undisclosed. U.S. officials deny reports of multiple secret annexes. But they ought to make all of its provisions public, ideally before the signing.

What we know from news reports and sources close to the negotiations is that the United States has committed to reducing the U.S. troop level to 8,600, from the current level of about 13,000, in the first 135 days of the agreement. During that time, the Taliban is to renounce al-Qaeda and other terrorist groups and open negotiations with an Afghan committee, including government officials as well as other leaders. If the United States concludes those pledges have been met, the withdrawal will continue; the administration reportedly committed to a full pullout over time.

Officials acknowledge the risk that the peace process won’t get off the ground. It remains to be seen whether the Taliban leadership can actually control the thousands of militants fighting under its banner. The Afghan government has its own problems following a bitterly disputed presidential election whose announced result — the reelection of President Ashraf Ghani — has been rejected by his leading opponent.

If these hurdles can be overcome, the talks could focus on the permanent cease-fire, a potentially landmark achievement in a nation that has been at war for 40 years. For that, the Taliban may demand the formation of a transitional government, which would oversee revisions to the constitution. The gaps between the sides are wide: While some Taliban leaders say they now accept the right of women to be educated and work outside the home, they show no willingness to preserve the democratic political system.

That brings us to the agreement’s biggest weakness: a lack of linkage between an Afghan political settlement and the final withdrawal of U.S. troops. An annex reportedly describes the pullout, Taliban counterterrorism commitments, peace talks and a permanent cease-fire as “interdependent.” But a full U.S. withdrawal before any settlement would likely lead to a new civil war and, possibly, a renewed Taliban dictatorship.

The Trump administration is right to test the Taliban’s willingness to stop fighting, break with al-Qaeda and negotiate in good faith with the Afghan government. Military commanders say they can manage with the lower troop level after the initial withdrawal. But Mr. Trump must be prepared to call a halt to the drawdown if the insurgents do not deliver. A rush for an Afghan exit in this election year may yield short-term political benefits, but it will invite a strategic disaster.

Read more: