KABUL, Afghanistan — A giant H has been painted on the broad boulevard in front of the American Embassy in Kabul, creating a new helipad that so far, embassy officials say, has only been used by Zalmay Khalilzad, the special United States diplomat who has been talking with the Taliban.
President Ashraf Ghani of Afghanistan usually uses the roads, moving in armored convoys that snarl traffic in the gridlock-weary capital.
The pecking order is clear. As American policy in Afghanistan seems bent more than ever on making a deal with Taliban insurgents to withdraw American troops from the country after nearly two decades of war, Mr. Khalilzad’s diplomacy is taking priority.
The talks between Mr. Khalilzad and the Taliban, while full of caveats, have raised some parallels to Henry A. Kissinger’s talks with North Vietnamese leaders, which presaged the American military pullout from South Vietnam in 1975 and the collapse of its government.
Mr. Khalilzad’s diplomacy has left many others in Afghanistan scrambling and unnerved, wondering if their interests have been sidelined in his talks with the Taliban in Doha, Qatar, 1,200 miles away.
Inside President Ghani’s palace, only a few blocks from the American Embassy and the American and NATO military headquarters, officials are alarmed by reports that Mr. Khalilzad might have discussed an interim government with the Taliban, which he assured them he had not.
That did little to allay fears in Mr. Ghani’s government — long protected and supported by the United States — that the Americans could well be headed for a separate deal with the Taliban if that is what it takes to get their troops out.
All traffic in front of the embassy was stopped as Mr. Khalilzad, whose title is special representative for Afghanistan reconciliation, flew into his personal helipad Sunday night from Kabul’s international airport, a two-mile helicopter ride away, after six days of talks with the Taliban in Doha. He immediately briefed Mr. Ghani.
The next morning United States Ambassador John Bass and the American military commander, Gen. Austin S. Miller, met with Mr. Ghani. Then Monday afternoon, Mr. Ghani, grim-faced, went on television to address his country and remind everyone on his insistence that peace talks must eventually be between Afghans.
“The victims of the war are Afghans,” he said. “So the initiative of peace should be in the hands of Afghans.”
Then Mr. Ghani made an extraordinary allusion to a former president, Mohammad Najibullah. “We insist on measures, because we are aware of the experience of Dr. Najib. We all know how he was deceived. The U.N. guaranteed him peace, but it ended up with a disaster.”
As nearly every Afghan knows, Dr. Najibullah left office in 1992, and an interim government promised by the United Nations led to even worse chaos and civil war. When the Taliban finally took Kabul in 1996, Dr. Najibullah took refuge in the United Nations compound, but the Taliban ignored diplomatic protections, dragged him out and hanged him from a lamppole.
That pole is right outside the presidential palace today, about halfway to the Embassy, and just across from C.I.A. headquarters.
Officials close to Mr. Ghani fear that the Americans are not only leaving an ally vulnerable by what they see as their overly enthusiastic overtures to the Taliban, but also risking the unraveling of 18 years of painstaking progress that has come at enormous cost of blood.
They are particularly frustrated in what they see as a sudden American lack of patience, little more than a year after President Trump announced his South Asia Strategy, a new policy for Afghanistan.
Mr. Trump called that policy a reversal of President Barack Obama’s telegraphing of a withdrawal to the Taliban, and the Afghans saw it as a longer-term pledge. It was not based on a timeline and gave military commanders on the ground expanded flexibility — or so it seemed.
The president’s own commanders on the ground were interpreting the new strategy to their Afghan partners as a long-term commitment.
Mr. Ghani is blamed for not helping his own cause in the short honeymoon with Mr. Trump’s strategy. His government was mired in internal bickering. The parliamentary elections in October, already delayed more than three years, were considered a disaster — most of the winners are yet to be seated. Presidential elections, scheduled for April, have been postponed to July.
Western diplomats have expressed fear that divisive and petty fights within the Afghan government risk squandering the moment’s strategic opportunities.
Since then, Mr. Ghani has only struggled further, alienated from much of the country’s political elite who have continued to build pressure on him.
Mr. Ghani has said he wants to change the way of governance, rooted in patronage and corruption. He also wants to decide who will negotiate with the Taliban, assuming those talks eventually begin.
But he picked a fight that angered other influential Afghans at a time when he needed a unified front against what has appeared to be a cohesive Taliban that is enjoying more and more success on the battlefield.
It is a point that was not lost on Mr. Khalilzad. In a briefing he held with Afghan media, he encouraged the Afghans to “seize this opportunity to put political differences aside and deal with this moment positively and urgently.”
Mr. Ghani is planning to run for a new term in the delayed presidential election. It is unclear whether his concerns are the fears of a leader seeing Afghanistan’s cycle of collapse repeat in front of his eyes, or those of a politician fearful of losing power.
For the Americans and their allies, however, the urgency for a deal before Afghanistan’s summer election is grounded partly in a fear that the voting, once again, might turn into a mess. That would leave them in an even weaker bargaining position against the Taliban.
On the American side, Mr. Khalilzad has kept embassy diplomats in the dark about his plans. Diplomats were not even sure what American policy on Afghanistan is anymore, and whether the president’s year-old South Asia Strategy was in the process of getting scrapped in a moment that felt like a rush for the exits.
One senior official joked privately that he was hoping President Trump would finally give his State of the Union speech, so officials could find out what American policy in Afghanistan actually is now.
At military headquarters next door to the American Embassy, so far as anyone knows, no order has actually come down to implement President Trump’s apparent call to send half of the 14,000 American troops home in the next months. American military numbers are believed to be falling, but only by not replacing personnel whose tours of duty are ending, while everyone awaits clarity from Washington.
Many American officials were quoting former American ambassador to Afghanistan Ryan C. Crocker, who compared the moment now to the American pullout from Vietnam in 1975, and derided Mr. Khalilzad’s peace negotiations.
“I can’t see this as anything more than an effort to put lipstick on what will be a U.S. withdrawal,” Ambassador Crocker said.
Others also have drawn the analogy to Vietnam, at least in some important respects. In both the Vietnam and Afghanistan conflicts, American political leaders increasingly saw them as unwinnable. In both, the Americans conducted negotiations directly with the adversaries of their allies, who were relegated to the sidelines.
Even so, John Prados, a senior fellow at the National Security Archive at George Washington University and an authority on the history of the Vietnam War, said it was premature to conclude that history was repeating itself.
“The key development in my opinion, is the extent to which this arrangement is between the United States and the Taliban, or takes into account the interests of the Kabul government,” he said. “Too soon to say.”