January 25: A small element of U.S. and Afghan National Army soldiers led by Staff Sergeant Robert James Miller was conducting a combat reconnaissance patrol through the Gowardesh Valley, Kunar Province, when they engaged a force of 15-20 insurgents occupying prepared fighting positions. After calling in close air support, Staff Sergeant Miller led a small squad forward to conduct battle damage assessment when over 100 insurgents ambushed the squad, Miller displayed extraordinary valour by drawing fire away from his squad, killing 10 insurgents in the process. His actions cost him his life, but he saved the lives of 7 members of his team and 15 Afghan National Army soldiers, he was awarded the Medal of Honor.
The U.S. government suspended, on March 27, 2008, AEY Inc. of Miami, Florida, a company hired by the U.S. military, for violating its contract. The company is accused of supplying corroded Chinese surplus ammunition made from 1962–1974, instead of the higher-quality Hungarian-made ammo from MFS 2000 Inc, to the Afghan National Army and police. United States Army-documents showed that since 2004 the company entered agreements with the U.S. government that totaled about $10 million. The papers also revealed the company received much larger orders in 2007 with contracts totaling more than $200 million to supply ammunition, assault rifles, and other weapons. Army criminal investigators were sent to look at the packages in January 2008. The House Oversight Committee announced plans to hold a hearing into the matter on April 17, 2008, at which the 22-year-old international arms dealer Efraim Diveroli and president of AEY Inc would face a congressional inquiry. The committee reported in June 2008.
April 4 - Mikhail Krotov, General Secretary of the Interparliamentary Assembly of the Commonwealth of Independent States, said that Afghanistan indicated its desire to become a CIS member. Afghanistan's parliament had an observeser status in the Assembly since 2006.
July 5: A Danish Leopard 2A5 hit an IED in Helmand Province, resulting in the driver's death. During the same contact with Taliban forces, a second tank was caught in an explosion but none of the crew were wounded.
July 12: British Special forces killed Mullah Bishmullah; a key Taliban leader at a command and control level in Now Zad, along with the death of Mullah Sadiquallah in late June, the Taliban suffered a significant blow to their logistics and facilitation chain in northern Helmand. 
July 13: Battle of Wanat. Taliban fighters attack a NATO base, killing nine American soldiers. A missile strike from a British aircraft killed Abdul Rasaq, a Taliban leader who led fighters around Musa Qala.
What made the Afghan campaign a landmark in the U.S. Military's history is that it was prosecuted by Special Operations forces from all the services, along with Navy and Air Force tactical power, operations by the Afghan Northern Alliance and the CIA were equally important and fully integrated. No large Army or Marine force was employed.
On October 1, 2008, the top American general in Afghanistan, David McKiernan, warned that the situation in Afghanistan could get a lot worse. The international forces within Afghanistan have not been able to hold territory they have cleared because of the lack of troops. For this reason the general called for an extra three combat brigades (roughly 20,000 troops). Without this urgent rush of troops the Taliban would be able to get back into the communities that were once cleared by international troops. The general went on to say that things could get a lot worse before they get better.
On October 1, 2008, a suspected U.S. drone fired a missile against militants inside Pakistan’s North-West Frontier Province near the Afghan border. It is believed that six people died in the incident. Attacks of such have drawn a stiff response from Islamabad, accusing the United States of violating their airspace.
December 19: US vows to send 3,000 more troops to Afghanistan.
On December 30, 2008, Pakistani security forces shut down the supply line when they launched an offensive against Taliban militants who dominate the Khyber Pass region. After three days of fighting, they declared the Khyber Pass open.