Every year as the snow melts, groups like Taliban and its affiliates, the Haqqani network, as also the Lashkar-e-Taiba (Let) cross over from Pakistan as a fresh fighting season begins in Afghanistan.
It is soldiers like Commander Kushal Sadat from Special Forces 222 who are called upon when terror strikes. The unit is based on the outskirts of Kabul and their mandate is to protect the Afghan capital from attacks by Islamic extremists challenging the democratic government.
Commander Sadat says his unit's task is to find, fix and kill. "This is close quarters combat. We need to come in with surprise, speed and aggression," he explains, as we witness the training of the soldiers.
Commander Sadat also says that the methods used by the terrorists in Kabul are the same as those in the 26/11 Mumbai attacks.
"The Mumbai Attack you had where the attack was at a scale that the normal police could not deal with it and the terrorist who take over building or hotels, then my force will be called upon with better equipment, better skills and better prepared to go and kill or capture them. Mostly, they are killed. So I am not really worried if it happens again. We will wrap it in a rapid way. For Mumbai attack, I think it took long as you did not have the experience," he said.
At the unit's base, we meet Pashtuns, Hazaras, Taziks and Uzbeks - all the major ethnic groups that comprise Afghanistan's complex mosaic of communities. This is as close to a national unit as possible but the balance isn't quite right yet. There are still few southern Pashtuns in the Afghan National Security Forces and a higher proportion of leaders are Tajiks.
Most Pashtun recruits, and those from other ethnic groups, come from the north and north-east, where resistance to the Taliban has been the strongest.
Some of those from provinces like Kandahar and Helmand worry for their families; as a precaution, they cover their faces, so the Taliban can't identify them.
In early 2011, one in seven newly-enlisted soldiers deserted the Afghan army and while literacy rates are very low, nationalism runs high.
"Earlier the Pashtuns and the Tajiks did not know each other that well... we will take care of Afghanistan now and the Talibs better not return," said Rashid, a Pashtun from the north.
His words reflect the new Afghan hope to withstand the Taliban onslaught by forging new ethnic alliances. But several questions remain.
Currently, the Afghan National Security Forces has 352,000 men, which will be brought down to 228,500 by 2017. The reduction is likely to take place in the first two years after NATO troops end combat operations, when the nation will be most vulnerable.
The cutback in troops is being seen as a strategy by the West to drop costs in the face of sluggish economy.
Money promised by the West is still short of what's needed to pay for the Afghan security forces.
Some experts believe it's the recession in the US and not major successes on the battlefield that will determine the endgame in Afghanistan.
Many ask what will happen once the money dries up. Will old ethnic fault lines resurface or will Commander Sadat's men be able to defend Afghanistan's fragile democracy?