Even as the Indo-Pacific emerges as a likely new theater of future armed conflict, America's longest war drags on in the landlocked mountains of Afghanistan.

With a Trump-era agreement with the Taliban still in effect, and as the May 1 deadline for the withdrawal of American troops from Afghanistan looms and violence escalates, U.S. Secretary of State Antony Blinken has proposed a series of measures to revive the stalled Afghan peace process.

The specifics of Blinken's plan have emerged in a letter to Afghan President Ashraf Ghani -- leaked to media alongside a detailed proposal delivered by Zalmay Khalilzad, the U.S. special representative for Afghanistan reconciliation -- and have created a stir in the region and beyond.

Here are five things to know about what's in the letter, what it means and how it may play out:

1. What is Blinken proposing?

Acceleration -- a word the letter uses twice in some form. The government in Kabul and the Taliban have not made much headway in their own negotiations, primarily because each side has refused to deal with the other. Generally, the Taliban consider the elected government in Kabul illegitimate and an American "puppet," according to spokesperson Zabiullah Mujahid, while the government in Kabul sees the Taliban as proxy warriors for the Pakistanis, according to Afghan First Vice President Amrullah Saleh. When intra-Afghan talks did begin late last year, even after a road map for withdrawal was set between the Americans and the Taliban, they dragged on and faltered, and violence escalated.

Now, with the May 1 deadline for the withdrawal of the 2,500 remaining American troops approaching, Blinken's fast-tracking the entire process. He's raised the stakes by telling the Afghans in power in Kabul by saying that no option, including full military withdrawal, is off the table. He's also issued a barely hidden warning to the Afghan president: "Even with the continuation of financial assistance from the United States to your forces after an American military withdrawal, I am concerned that the security situation will worsen and that the Taliban could make rapid territorial gains."

His penultimate words are perhaps the iciest: "I am making this clear to you so that you understand the urgency of my tone regarding the collective work outlined in this letter."

2. Why does it matter?

Blinken telling the elected Afghan government to share power with those it has been fighting for two decades is a bold move. Critics say it is like the U.K. or Japan telling U.S. President Joe Biden he needs to share power with the same people who attacked the Capitol on Jan. 6.

But unlike QAnon, the Taliban control vast swaths of Afghanistan. They run parallel courts and community markets and trade networks. They have ruled the country before and have international allies with nuclear weapons, such as Pakistan. The Taliban have an embassy in Qatar.

Still, Blinken's proposal for power-sharing is a serious shift in the American position. He asks Ghani to "move urgently" on such tasks as developing "the foundational principles that will guide Afghanistan's future constitutional and governing arrangements" and developing "a roadmap to a new, inclusive government." Basically, he is telling the Afghan government to let the Taliban in and rethink the constitution, all so that a "permanent and comprehensive ceasefire" can be reached.

3. How does Blinken's proposal differ from previous peace plans?

Peace is a rare commodity in Afghanistan and the region. Blinken thus also proposes something else that loops other powerful actors into a wider berth: cooperation.

For the last two decades, Afghanistan has been not only a battleground between the Taliban and the Americans, but also a stage for complex proxy warfare between several regional players.

India and Pakistan have fought it out in the mountains of the Hindu Kush by backing different groups: New Delhi has favored the Tajik speakers of the north, while the Pakistanis have worked closely with the Pashtuns of the south.

As they have in other parts of the Middle East, the Iranians and the Saudis have backed their own Shiite and Sunni warlords and militias in Afghanistan.

The Chinese, who have vital mining and trade interests in the war-torn country, and the Russians, who have reportedly offered bounties for American soldiers' deaths, have trusted their own "megaproxies" like the Pakistanis or the Indians to do their bidding.

But Blinken's letter is both unusual and controversial because it calls for bringing not just the Taliban and the government in Kabul together. It calls for the United Nations to convene a conference with foreign ministers and envoys from Russia, China, Pakistan, Iran, India and the U.S. "to discuss a unified approach to supporting peace in Afghanistan."

Never have the Pakistanis and the Indians sat down at the same table to discuss Afghanistan. Nor have the Russians and Iranians been in the same room as the U.S. for many conferences, much less to end one of the longest-running wars in living memory.

Perhaps most significantly, it includes China in the mix, acknowledging Beijing's role not only as a regional player with leverage over other important players like Pakistan, but also as the other superpower at the table.

4. Why does this seem familiar?

The American plan to secure a political settlement by enlisting major powers and regional players and inviting them to a huddle resembles the multilateral approach taken at another conference in late 2001, just months after the Sept. 11 attacks. As the last of the Taliban regime's remnants melted away under the pressure of American B-52 bombing runs in southern Afghanistan, an international conference was held in Bonn, Germany, to lay the foundations of the modern Afghan state.

Anti-Taliban warlords and politicians were strung together by international diplomats to pledge allegiance to Hamid Karzai and formed the basis of the modern Islamic Republic. The Istanbul conference Blinken proposes would not mark the first time several actors gather in one place to try fixing Afghanistan. But times have changed.

"The context is now very different," argued Marvin Weinbaum, director of Afghanistan and Pakistan studies at the Middle East Institute, in a briefing Monday. "The [Bonn] conference, held in the wake of a Taliban rout, occurred in the absence of an Afghan state. Today, there is an elected constitutional government that would be replaced. A Taliban insurgency is threatening to impose its own form of government."

"Underlying the U.S. initiative is the belief that it is possible to replicate a Bonn-style international conference to create, as in 2001, the groundwork for an Afghan state," Weinbaum wrote. "What this approach offers in hope, it lacks in practicality."

"We also forget that the Bonn conference was designed only for the victors and could not have succeeded if the combined efforts of the U.S., Russia, and Iran had not dragooned the several Afghan parties into reaching an agreement," he noted. "But international goodwill toward Afghanistan that existed two decades ago is long gone, and all its neighbors are currently acting according to their hedging strategies."

Above all, there is no evidence to suggest that the Taliban would be any more amenable to compromise on substantive issues if the negotiations were moved from Doha. From the days when they destroyed Buddha statues in Afghanistan, the Taliban have proved indifferent to international pressure when set on their goals.

5. What is at stake?

The stakes are high.

A withdrawal would end America's longest war but also embolden the Taliban.

The invasion of Afghanistan had vast international support after the Sept. 11 attacks. For the U.S. and its allies, hunting down and killing Osama bin Laden and his al-Qaida network was as important as toppling the Taliban regime that had sheltered him. But sinking trillions of dollars into a war effort that crept away from its original mission while spending even more political and financial capital -- and the lives of 2,300 American troops -- to sustain an Afghan government widely seen as corrupt has left the U.S. with precious few options.

"The administration is keen to signify its commitment to moving the needle on the peace process, if only so that it can create the conditions for a relatively smooth withdrawal that it would prefer comes sooner rather than later," said Michael Kugelman, deputy director of the Asia program at the Wilson Center. "But at the end of the day, the Blinken letter is something that the administration can point to later, whenever it withdraws. 'Look,' it can say. 'We tried our best to get the peace process going. We've done all we can do, and now we're passing the baton to the Afghans.' So in a sense, the Blinken letter, even while laying out an ambitious plan for U.S. engagement on a peace process, can be seen as the precursor to an exit strategy."

As vice president, Biden opposed then-President Barack Obama's "surge" in Afghanistan -- a much-publicized expansion the U.S. military footprint that was as costly was it was ineffective. In campaign mode, Biden agreed with opponent Donald Trump, promising to "end the forever wars in Afghanistan and the Middle East."

But while staying too long could carry a domestic political cost and put more American soldiers at risk, leaving too quickly could sink the country into chaos.

"It's a diplomatic maneuver that is both brilliant and self-serving," said Uzair Younus, visiting senior policy analyst at the bipartisan United States Institute of Peace. A lasting peace would be seen as "a master stroke of American diplomacy," Younus said.

"Failure will allow the U.S. to say that despite sustained military, economic and diplomatic support, Afghanistan was a lost cause and that the U.S. did all that it could possibly do to bring lasting peace to the country," he said.