(CNN) The last American military flight left the airport and disappeared into the Kabul sky on Monday -- and minutes later, the Taliban flooded the streets around the city's last exit point, filling the night with celebratory gunfire.
It was a decisive and humbling final chapter to the United States' longest war, a two-decade effort that unraveled spectacularly in the space of a few weeks.
Standing on the runway on Tuesday, Taliban spokesman Zabihullah Mujahid framed the militant group's dramatic takeover of Afghanistan as a nationalist success, telling a small crowd: "This victory belongs to us all."
But for thousands of Afghans, the final Western flights took with them a last chance to leave the country. Many now fear their new realities; in particular, women, religious minorities, LGBTQ people, journalists and others face brutal treatment under the group's radical interpretation of Sharia Law.
And for the Taliban's leaders, a rapid transition to national governance beckons. The group has no experience of running a traditional administration, and showed little familiarity with geopolitics during its five-year reign two decades ago. Their sincerity and capability now has repercussions for 38 million Afghans, many of whom will be displaced or thrust into economic crisis.
Afghanistan is a very different country to the one the Taliban ruled between 1996 and 2001. Most Afghans don't even remember that era -- more than 60% of the country is aged under 25. It is urbanizing, diverse, and better connected to the world, all of which place it in stark contrast to the war-torn nation the Taliban conquered 25 years ago.
What the Taliban now do with that country is arguably the world's most pressing geopolitical question.
"This is one of the most dramatic changes in government in the modern era," Benjamin Petrini, a research fellow at the International Institute for Strategic Studies (IISS), told CNN.
The West is "pulling out not only ourselves but all the human resources that have worked with us for 20 years," he said. "Those will be replaced with what? That's a question mark."
It's a question that reverberates not just through the region, but around the world. As they weigh up whether and how to recognize the country, global governments have mostly been unmoved by the Taliban's repeated promises that they have changed.
Its leadership has repeatedly insisted that women will play a prominent role in society, that they will not seek retribution against their political enemies, and that their regime will be "inclusive" -- but they have not shared details of what they mean by their Sharia Law-driven social policies, and their fighters have repeatedly shown less restraint in recent months.
That leaves a number of possible roads forward for Afghanistan -- ranging from cooperation and restraint to civil war and global ostracism.
"I don't see how (the Taliban) are going to sell out all of the people they've been fighting with for 20 years," Gareth Price, a senior research fellow at London-based global affairs think tank Chatham House, told CNN -- raising the specter that the group will turn inward and embrace the radical tendencies of many of their soldiers. "And then what?"
The Taliban's rule at the end of the millennium was a global anomaly. "They weren't a government," said Price, who monitored the country at the time for the Economist Intelligence Unit. The group's priority was "literally just about imposing Sharia Law," he said.
They did so brutally -- floggings and public executions were common, and women were mostly consigned to their homes.
But now the group's leaders are in unfamiliar territory. "When they arrived last time around, it was after a civil war. There was nothing. Now they're inheriting a system of government that, however imperfect, does exist," Price said.
"The question that no one knows the answer to is how the Taliban conceive of government."
As it assembles some form of political administration, observers are keenly watching whether Taliban leaders will allow for a diversity of viewpoints.
"To what extent are the Taliban going to be able to lead an inclusive process of government; are they going to be able to include different factions of society, and other ethnic groups?" asks Petrini, echoing the queries of the world's leaders.
What the Taliban do with the security sector is crucial, he adds; the Taliban may naturally be inclined to wipe out and replace the police and military, in order to ensure loyalty among those forces. But such a move could open the door to further instability and protest, and damage the government's legitimacy in the short term.
"They will make a decision very soon either to form a coalition government or establish a monocratic Taliban government," Antonio Giustozzi, a terrorism and conflict expert at the UK-based Royal United Services Institute (RUSI), told CNN. But whichever route they go, their access to cash will be an immediate priority.
"The Taliban as an organization is going to suffer -- there won't be money," Giustozzi said. "Some countries that support the Taliban might be able to give a little bit ... but that is not a lot compared to what Afghanistan was getting before from the US and the Europeans."
For the people of Afghanistan, a fundamental concern is how strictly the group will police the lives of Afghans.
Already, worrying signs have emerged: Afghan commandos, members of the media, singers and various other members of society have been targeted, threatened, dragged from their homes or executed in recent weeks.
And the Taliban have already conceded a fundamental flaw in their overtures to the international media; even if they wanted to fulfill each promise of inclusion and restraint they have made, their rank-and-file militants may not. The group told working women to stay home last week, admitting they weren't safe in the presence of their own soldiers.
"The Taliban are going to have to establish themselves as legitimate, so they can't necessarily rule with an iron fist," Petrini said. "(But) in the big cities there's going to be a dramatic change in the short-term. It's undeniable that there's going to a reverse in human rights standards, in women's rights, women's access to labor.
"All of these things that we measure as metrics and that have been slowly improving in Afghanistan in the last 20 years, they're going to be reversed in the short term."
Afghanistan's society, demography and culture has undergone wholesale changes in the past 20 years -- but all of it is fragile, experts warn.
"It's a young country and it varies a lot. A lot of women have been educated and empowered," said Price. One of its most popular television programs was the "X Factor"-style talent show "Afghan Star," he notes -- a remarkable feat in a country where singing had been outlawed years before.
"But that was all because of huge Western aid money going in. What didn't happen was the development of a permanent economy," Price added.
"There is a large number of women who are used to living more freely (and) more people in the professional sector -- but are they staying or not?" asks Giustozzi.
The Taliban's takeover has already pushed the country to the brink of economic collapse. Afghanistan's banks remain shuttered two weeks after their takeover, and many people can't access cash.
"No one has money," one current employee of Afghanistan's central bank told CNN last week. The employee, speaking anonymously due to fears for their safety, said many families don't have enough money for their daily spending and some paychecks have been halted.
The hardships facing a new generation of Afghans is exemplified by Rohina Afshar; a young female YouTuber, whose job would have been unimaginable at the end of the 1990s. "I was the only breadwinner in my family as my father is dead and my brother is not old enough to work," she told CNN earlier this week. "Now I am jobless, I am too scared to go out and we have got no income at all. I don't know how we can survive this situation."
There is little doubt that the Taliban's foremost domestic problem, if they decide to form a traditional government, is the freefalling economy. International agencies are sounding the alarm about multiple humanitarian crises in the country; the UN warned on Tuesday that 18 million people in the country need assistance urgently to survive.
"A humanitarian catastrophe looms," UN Secretary-General António Guterres said in a statement. "People are losing access to basic goods and services every day."
The country's healthcare system is among them, Médecins Sans Frontières (MSF) country representative Filipe Ribeiro warned on Monday. "The overall health system in Afghanistan is understaffed, under-equipped and underfunded, for years. And the great risk is that this underfunding will continue over time," he said.
And a hunger crisis is taking hold. Up to 14 million Afghans could face starvation as early as September, World Food Programme (WFP) Executive Director David Beasley has warned.
"Because of Covid, conflict, economic deterioration, the numbers of people marching to the brink of starvation has spiked to now about 13 to 14 million people," Beasley told CNN on Tuesday.
He said that the WFP is "running out of money," adding that the agency requires $200 million additional funding to continue operations in Afghanistan for the rest of the year. "If we don't receive these funds, then you're talking about millions of people, just like you had in Syria, that very well could start migrating, fleeing out of the country desperate for food."
It remains to be seen how easily the Taliban will allow assistance to flow through the country. And many warn that the situation could be worsened if the international community imposes financial punishments on the Taliban.
"Sanctions -- unless very carefully designed -- will inflict pain on innocent Afghans' communities and have almost no impact on the Taliban," warned Rory Stewart, the UK's former minister for international development, as the G7 discussed its next steps.
"It looks as if it's going to be very tough. People are still going to work in the hope they will get paid, but not many will keep working for free," said Giustozzi. "If the money is not released, it will be a huge humanitarian emergency."
And he questioned how urgently the Taliban would address the crisis -- suggesting that some within the leadership may see keeping the country poor as their "best weapon," because it exacerbates the threat of an exodus of refugees towards Europe and therefore encourages European nations to send aid anyway.
"In a year or two from now, they will need to come to our aid anyway," Giustozzi said, imitating a potential line of thinking within the Taliban. "They think they can ignore us, but they can't."
Every move made by the Taliban in the coming weeks will be analyzed in several time zones, as global governments grapple with the complicated question of how closely they should cooperate with the group.
"The people who have been running the Taliban machinery understand that they need to get international recognition," Giustozzi said. "Afghanistan is a landlocked country, they don't have any money -- so in the short-term they understand that they need support."
The world has mostly been non-committal so far, and global organizations like the World Bank have already suspended operations in the country.
"But I don't think the Taliban will be as ostracized as they were 20 years ago," Petrini said. Experts have noted that, like Afghanistan, the world has changed in the past two decades -- and the bar to global acceptance may now be lower.
"The international system is not what it was in the era of cooperation in the 1990s, (and) there is way more acceptance, willing or not, even of regimes that impede human rights," Petrini said.
"The Taliban will be quick to say, 'What about Saudi Arabia? You do a lot of business with them," added Giustozzi, drawing comparisons between the two countries' human rights records and treatment of women.
G7 leaders have discussed whether to recognize Afghanistan's new government, while US President Joe Biden has said he wants to see "harsh conditions" applied to the Taliban, particularly in how they treat women and girls, before lending their government legitimacy. He said he was open to applying sanctions too.
But should the Taliban disregard Western opinion, the world's ability to respond may be limited. "I'm not sure that the international community has a tool that is really capable of modifying Taliban behavior," Nathan Sales, the Ambassador-at-Large and Coordinator for Counterterrorism at the US State Department during the Trump administration, told CNN.
"In 1996, they were completely marginalized and isolated -- you could count the number of governments that recognized them on one hand, but it wasn't a priority for (the Taliban)."
Sales suggested that the group may have grown savvy in dealing with foreign governments. "Unfortunately the Taliban has been playing the long game, in a sophisticated way. I think they banked on Western fatigue (and) were able to present to the West a sufficiently reasonable face at the Doha talks," he said.
And a similar Western attitude may unfold as the Taliban transitions to governing. "The temptation in elite international circles is going to be to issue a world-weary sign and say, well, 'We have to be realistic,'" Sales said.
"The main question is whether we are going to put the Taliban in that category of groups that are sponsoring terrorism globally?" added Petrini. On Tuesday, those concerns were heightened when al Qaeda praised the Taliban for taking control of Kabul, in an English language written statement from its media wing As-Sahab.
Price agreed that any indication the Taliban were aiding terrorists would be a global red line. "But would anyone take them at their word? I don't think Western countries would," he said. "How do you tell, when these sorts of things are so blurred?"
Meanwhile, the Taliban's treatment of domestic opposition could become another global measuring stick.
Afghanistan has already seen pockets of resistance -- much of it closely watched, and some brutally stifled, by Taliban troops. "That is a complaint of having a young population that is connected to the internet, that knows what there is in the world, and that looks for models of protest and resistance," said Petrini.
"Those protests are a sign that the demographics have changed and that the system is more complex," he added. "There are going to be young students and a middle class that want to have a voice, and the Taliban are going to have to reckon with that."