The West left Afghanistan. The Taliban reloaded. Monday was the result.

After months of fighting Afghan National Security Forces (ANSF) in the northern province of Kunduz, Taliban insurgents overran its capital, a city of 300,000 and the fifth largest in the country. One of Afghanistan’s most prosperous, once.

The fighting continues; the situation in Kunduz is fluid, its outcome unclear. But the Taliban siege represents a major setback for Afghanistan’s new National Unity Government, symbolically and in practical terms. Kunduz, and Kandahar in the south, were the last urban centres held by Taliban fighters after western troops arrived in Afghanistan following the September 11, 2001 terrorist attacks in the United States. Among those troops were thousands of Canadian soldiers, 158 of whom didn’t come home alive.

Kunduz province is an important agricultural centre, as well as a trade and transportation hub that connects the rest of Afghanistan to neighbouring countries to the north. Kabul is 150 kilometres south of the provincial capital.

On paper, the Taliban should not have stood a chance; their fighters were vastly outnumbered in and around Kunduz city by ANSF members, including regular Afghan Armed Forces troops and Afghan National Police, by a four-to-one ratio, according to some accounts this week. Nevertheless, a three-pronged insurgent assault on the ancient city caught government forces off guard.

Dozens of ANSF members have been killed and captured, while hundreds more have reportedly abandoned their positions and fled. Mohammad Omar Safi, appointed Kunduz provincial governor in December by Afghan president Ashraf Ghani, was outside the country when the insurgents’ attack began Monday, raising eyebrows and suggestions of a conspiracy. Safi’s whereabouts remain a mystery; his former deputy is now ostensibly in charge.

American special forces, still in the area after the NATO-led International Security Assistance Force (ISAF) mission wound down last year, managed to penetrate Kunduz city from its outlying airport, and have helped the ANSF beat back insurgents. The U.S. has also conducted airstrikes on Taliban locations surrounding the capital. Fighting continued through Friday.

The implications are sobering. The insurgency is resurgent, while the ANSF has again shown itself incapable of defending and securing the country without international help.

The United States has reduced its troop count, from approximately 100,000 soldiers in 2010 to 9,800. Canadian and other foreign troops wound up their military operations last year, after spending one trillion dollars battling the insurgency and assisting with civilian-led reconstruction efforts. Canada spent at least $12 billion in Afghanistan from 2001 to 2014, most of that on a frustrating combat assignment in Kandahar, from 2006 to 2011.

Canada now has “a limited number” of personnel in Afghanistan, men and women “serving in support functions at the Canadian Embassy in Kabul,” according to a military spokesman this week. “They also serve in a variety of individual exchange positions with allied forces. In order to maintain operational security and ensure the safety of Canadian Armed Forces personnel, no further information is available at this time,” he added.

The Taliban, of course, never left. They maintain strongholds in southern provinces such as Kandahar, and have continued their attacks across the country this year, including a string of suicide strikes in and around Kabul International Airport two months ago, which killed 55 people and injured hundreds more.

Kunduz represents the biggest Taliban victory — militarily, politically, as a propaganda piece — in a decade. But it likely won’t be their last.

The latest situation report from the United Nations Security Council, released in September, describes a “sustained conflict, which grew in both intensity and geographic scope (in the three previous months and) continued to result in significant casualties and displacement among Afghan civilians, as the ANSF sought to counter the efforts of insurgent groups to undermine the Government.”

The ANSF is overwhelmed, the UN report makes clear. Since June this year, “the concerted effort by anti-Government elements to capture and hold district centres in a number of provinces…resulted in the capture of seven district centres, a significantly larger number than in previous years.”

The UN documented 4,921 civilian casualties since June, “a one percent increase in total civilian casualties compared with the same period in 2014. The vast majority of civilian casualties (90 percent) resulted from ground engagements, improvised explosive devices, complex and suicide attacks and targeted killings.”

Perhaps most tellingly, 103,000 Afghans were displaced from their homes in the first half of 2015, a 77 percent increase compared to the same period last year. The largest number of displaced persons — by far — was recorded in Kunduz Province, the U.N. reported.

International security expert Jason Campbell studies Afghanistan for Virginia-based RAND Corporation. He was in northern Afghanistan last October. The Taliban surge inside Kunduz this week should not surprise, he said in an interview with the National Post. “This wasn’t an overnight sensation,” he said. “The tension has been rising in Kunduz for a number of years. It’s been a persistent simmer.”

Yet the city was left vulnerable. The number of assets on the ground isn’t as important as their capabilities. Kunduz was beset by “an economy of force,” Campbell says, with the best of the ANSF assigned elsewhere. Kunduz was reliant on Afghan Local Police, a thinly trained and equipped mix of militiamen and uneducated villagers whose loyalties have frequently been questioned.

There is a peculiar socio-cultural dynamic in the province as well. Kunduz has one of the most diverse ethnic mixes in Afghanistan; the majority of the population is Pashtun, a tribal people who also dominate the south, in provinces such as Kandahar, and northwestern Pakistan. The Taliban have exploited ethnic divisions wherever possible to undermine the national government’s efforts.

“There have been reports of extrajudicial acts against the Pashtuns in Kunduz” by members of other ethnic groups, Campbell noted. In an effort to balance interests in the province, President Ghani appointed Omar Safi as governor in December. Safi is Pashtun.

The fact that Kunduz was overrun by Taliban on Safi’s watch — and that Safi was absent, reportedly abroad during the siege — could “be seen as something of an indictment of Ghani,” Campbell said.

The question now, of course, is whether the Taliban can continue to mass and reassert the control they once had in other Afghan provinces, including Kandahar. Events this week suggest the future depends on how Afghanistan’s allies respond.

After all that’s be spent in Afghanistan since 2001, with disappointing if not predictable results, it’s unlikely that Ottawa — or Washington, London and Paris — would consider increasing their military commitments to what is arguably a lost cause.

“I think that from a strategic perspective, Afghanistan was never a winnable war,” Thomas Johnson director of culture and conflict studies at the Naval Postgraduate School in Monterey, Ca., told National Public Radio’s Tom Ashbrook this week, after the fall of Kunduz. “We’ve had many, many politicians, military folks and analysts that have tried to wish a reality onto Afghanistan, and they’ve been wrong, time and time again.”

No more troops, but more treasure will be spent. Canada’s top diplomat in Kabul explained earlier this year that Canada has committed another $227 million towards development assistance in Afghanistan, through 2017, and another $330 million to supply the lacklustre ANSF. “There is a buzz in the air these days in Afghanistan, a sense of optimism, and I think we all feel it,” wrote Deborah Lyons, in her February, 2015 public “dispatch.”

Canadians are understandably skeptical of the tired “optimism” refrain. That buzz in the air wasn’t the sound of peace. It was the Taliban, on the march.