SECURITY situation in Afghanistan is worsening day by day. Reports speak of coordinated attacks by Taleban on checkpoints near Tarin Kot, the capital of the Uruzgan province. Attacks centered around the prison on the city's outskirts, though the insurgents were unable to rescue any prisoners as Afghan forces took all the prisoners with them when they fled. On Thursday, there was an explosion in the Afghan capital, Kabul, as crowds gathered to commemorate the 15th anniversary of the death of Ahmad Shah Masoud, a leader of the anti-Soviet Mujahedeen in the 1980s. Last month, two faculty members of the American University of Afghanistan, one American and one Australian, were abducted at gunpoint from a road near the university in Kabul. All US efforts to rescue them have failed. Tarin Kot is the third Afghan provincial capital to come under Taleban threat in recent months, along with the city of Kunduz in the north and Lashkar Gah in the Helmand province. Helmand's capital, Lashkar Gah, has been under heavy pressure from the fighters. Tarin Kot and Lashkar Gah may resist an onslaught by Taleban. We know what happened to Kunduz. It was captured by insurgents last October before being driven out by US-backed Afghan troops. But that does not alter the fact that 15 years after the US invasion, Afghanistan remains a violently contested and unsettled land. Violence has grown in intensity and scope. There has been a steady rise in security-related incidents in 2015 compared to 2014, and security is deteriorating even in areas that have never been under the sway of Taleban. Insurgents have undoubtedly expanded their territorial reach over the past year. According to a recent UN report, Taleban are spread through more of Afghanistan than at any point since 2001 when they were toppled from power. They now control more territory than in any year since 2001, with the UN estimating that nearly half of all districts across Afghanistan are at risk of falling. By any reckoning, 2015 was a bloody year for Afghanistan, with a resurgent Taleban killing or wounding an estimated 16,000 soldiers and policemen. The US has spent more than $110 billion in US taxpayer funds to support reconstruction in Afghanistan since 2001. It is now America's longest war and yet the outcome has been anything but the sudden collapse of the Taleban regime, once the American forces entered Afghanistan, led one to believe. In the euphoric days of 2001, hopes were so high that some dreamed of a "Great Central Asia" with "a magnetic democratic Afghanistan" at its heart. Now there are fears of a "transfer of Afghan fire" onto the territory of post-Soviet Central Asia. And "the magnetic democratic Afghanistan" lacks a central government whose writ runs throughout the country. Weakness of the government affects the morale and efficiency of the army. So Afghanistan is proving President Barack Obama's Vietnam. US Secretary of Defense Ashton Carter may think that "the Taleban's existence in Afghanistan is only a temporary phenomenon." But just like the Vietcong in Vietnam, the Taleban strongly feel that they will eventually wear out any government in Kabul and Washington. However, as long as the conflict remains unresolved, Afghans' agony will continue. So the next US administration must change course and develop an exit strategy that offers some face-saving way out for both parties. It should resist the temptation to pour money and resources into a failing enterprise with no end in sight. To continue the war because of "all the blood and treasure we've invested in Afghanistan over the years" (Obama's argument) is doing the same thing again and again expecting a different result. So all should strive for a negotiated end to the war. Taleban must be an integral part of any political settlement which should also be acceptable to India, Pakistan and Iran (among others) if it is to be workable and durable.