All roads in Afghanistan lead to bad outcomes for the US, which doesn't want to leave behind a disintegrating and violent country but also is wary of spending billions more and risking more US lives on America's "forever war."

Just days after the top US negotiator said the US and Taliban had reached an agreement in principle, a Taliban-claimed bomb attack on Thursday killed an American soldier and a Romanian soldier. The US wants the Taliban to reduce violence as part of the agreement.

The roughly 14,000 US troops in Afghanistan forces are stopping the Taliban from gaining even more than half the country and a hasty withdrawal will certainly have consequences — from bad to catastrophic.

Just because the US plans to pull out, that doesn't mean the situation in Afghanistan will become any less of a crisis — it will just be someone else's crisis.

There are concerns ISIS not only poses a threat to Afghanistan, but will also use it as a launching pad for global attacks, and that the Taliban and the central government won't have the capability or ambition to stop it.

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After nearly 18 years of conflict in Afghanistan, the situation has become so dire that the US is negotiating to withdraw its forces from the country with the terrorist organization it originally invaded to destroy following the 9/11 attacks.

The war has been a costly disaster for the US and has gone on so long that it's virtually been forgotten on the homefront. During Defense Secretary Mark Esper's confirmation hearing in July, he was not asked a single question about Afghanistan, even as US service members continue to be killed there.

In 2019 so far, 16 US service members have been killed in combat in Afghanistan.

Meanwhile, ISIS has gained a foothold in Afghanistan and recently killed 80 in a suicide bombing at a wedding celebration in Kabul, the capital of a country that earlier this year was designated the most dangerous place in the world by the Global Peace Index.

It is in this context that the US is attempting to tiptoe away from the conflict and is currently in negotiations with the Taliban over a plan to withdraw troops from Afghanistan

The Taliban is still staging deadly attacks and killing American soldiers amid the peace talks with the US

But while peace talks between US diplomats and the Taliban are reportedly progressing, the Afghan government isn't involved in the talks, which means the Trump administration is betting on the Taliban, an extremist group that continues to stage brutal, deadly attacks on Afghan security forces as well as civilians.

The Taliban in recent weeks have been accused of suicide attacks, a roadside bomb that killed 35 bus passengers and blasts that devastated markets and city centers.

An American was also killed in a Taliban-claimed attack in Kabul on Thursday, which came just several days after the top US negotiator in the US-Taliban talks said a peace deal had been reached "in principle."

Under the deal, 5,000 US troops would withdraw from five bases in Afghanistan within 135 days.

"We have reached an agreement with the Taliban in principle but of course until the US president agrees with it, it isn't final," Envoy Zalmay Khalilzad recently told TOLO news channel.

Meanwhile, Secretary of State Mike Pompeo has reportedly refused to sign the deal, which is a sign of how shaky it is.

"It is extremely difficult to choose between negotiating with an Afghan government, which seems to be failed at this point," and the Taliban, Anthony Cordesman, the Arleigh A. Burke chair in strategy at the Center for Strategic and International Studies, told Insider. "On the civil side, there's no clear sign of progress. Tbe government is dependent on outside aid and will remain so indefinitely."

Indeed, all roads in Afghanistan lead to bad outcomes for the US, which doesn't want to leave behind a disintegrating and violent country but also is wary of spending billions more and risking more US lives on what's been dubbed America's "forever war."

President Donald Trump in August told reporters, "We've been a peacekeeper there, in a way, for 19 years and at a certain point you have to say that's long enough."

Most Americans, including a majority of veterans, say the war in Afghanistan was not worth fighting, according to a recent Pew Research Survey.

The roughly 14,000 US troops in Afghanistan are there to train the country's still struggling military, as well as launch targeted raids against terror groups. The US doesn't have many things urging it to stay in Afghanistan, but these forces are stopping the Taliban from gaining even more than half the country and a hasty withdrawal will certainly have consequences — from bad to catastrophic.

"This peace may end up dividing the country," Cordesman said. "You have to worry about the fragmentation of Afghanistan."

And it could spell the end of the current Afghan government and the limited gains for democracy, women's rights and education fostered by the US.

"We can say, if the US does not provide financial support and firepower, the [Afghan] government will be overthrown," said Mark F. Cancian, a retired US Marine Corps colonel and a senior advisor for the Center for Strategic International Studies (CSIS) International Security Program.

US Soldiers from the 48th Infantry Brigade Combat Team scan territory in Afghanistan. (U.S. Army photo by Sgt. Jordan Trent) Sgt. Jordan Trent/US Army

Changing missions

The war in Afghanistan has slogged on for nearly two decades — costing billions of dollars and claiming the lives of over 2,400 Americans — and, as Cancian outlines in a report for CSIS, it was riddled with problems from the start.

From ignoring the lessons of the Soviet Union, which found Afghanistan easy to overtake but hard to rule, to a lack of understanding about Afghan culture and the Taliban's motivation, American hubris brought on the invasion and the "forever war." And the eventual goals of the Afghanistan incursion — the eradication of al Qaeda, at first, and then nation-building — far outpace the resources that the US expected to put in to the war.

"The transformation of Afghanistan envisioned by those who advocate for nation-building will take decades, perhaps even generations of U.S. military presence," Cancian's report states, citing South Korea, Japan, and Germany as examples of countries that moved from authoritarianism to democracy with the help of US involvement over decades.

Read more: US negotiators trying to end the war in Afghanistan are frustrated that Trump keeps giving the Taliban a stronger hand

But Afghanistan is not South Korea, Japan, or Germany; it has its own history, and its own history with occupation. Adding to that is its difficult terrain, tribal structure, and particular cultural, religious, and social values, none of which were particularly pertinent to the conversation when the US decided to involve itself in the country.

As Steve Killelea, the founder and executive chairman the Institute for Economics and Peace, put it to Insider in June: "The real issue is the inability to solve these conflicts once they start. If we look at Afghanistan, that's been going 18 years now ... and it's hard to see what the practical solutions can be other than a peace deal with Taliban."

But just because the US plans to pull out, that doesn't mean the situation in Afghanistan will become any less of a crisis — it will just be someone else's crisis.

An opportunity for ISIS

National security experts warn that a US withdraw opens a big door for ISIS, which is estimated to have somewhere between 2,500 to 4,000 fighters in its Afghanistan affiliate — known as ISIS Khorasan. There are concerns ISIS not only poses a threat to Afghanistan, but will also use it as a launching pad for global attacks, and that the Taliban and the central government won't have the capability or ambition to stop it.

Jennifer Cafarella, the research director at the Institute for the Study of War, told Insider that the US "should be very concerned about ISIS using Afghanistan to stage attacks on the West" and that withdrawing US forces makes it harder to disrupt ISIS's operations there "and thereby cedes greater opportunity for ISIS to pursue external operations."

"ISIS in Afghanistan is certainly a serious threat. After a withdrawal, the US could likely still conduct some limited counterterrorism operations but not at the scale that would be necessary to prevent ISIS from generating new cells," Cafarella added. "If we focus only on responding to the attack cells, once formed, we are at risk of overstretch. The risk is that, sooner or later, attack cells will start to slip through due to sheer volume."

UN Secretary-General António Guterres has issued similar warnings in recent weeks, stating that ISIS still has as much as $300 million following the collapse of it's self-declared caliphate and "with none of the financial demands of controlling territory and population." Guterres said Afghanistan might be the "best-established conflict zone" in terms of those attracting foreign extremist fighters in the region, the Associated Press reported.