NATO Forces Launch Major Taliban Assault

The thunder of British guns late Wednesday night marked the star of an ambitious NATO operation to drive the Taliban out of the town of Sangin in southern Afghanistan, CBS News chief foreign correspondent Lara Logan reports exclusively. As they fired, U.S. forces from the 82nd Airborne were dropped into Helmand Sangin valley under cover of darkness.

Daylight saw a Canadian 155 howitzer airlifted into a big multinational fight under the banner of NATO. The combat mission there, in many ways, is redefining the organization's more traditional peacekeeping role.

British forces have carried most of the burden in Helmand since moving into the area last summer. Royal Marines set up blocking positions Thursday to prevent the Taliban reinforcing their fighters facing U.S. troops further north. They say they are fighting two wars there: one against the Taliban and the other against the drug trade that finances them.

The poppy fields are at the center of the fight in southern Afghanistan where U.S. and British forces are leading NATO's battle against the Taliban for control of that vital area. It is there that most of Afghanistan's poppies are processed into opium and heroin.

"I think this area, the Sangin Valley is essential. Once we do control this area, then things in Helmand will be going much more in our favor," says Lt. Matt Hills with the British Army.

The Taliban are proving to be a resilient enemy. They control large parts of Helmand province, where the terrain is rugged and difficult. Since being defeated six years ago, they've come back stronger than ever, mostly thanks to the sanctuary they've enjoyed across the Afghan border inside Pakistan.

"We are inevitably always chasing ghosts, as we say. It is difficult to differentiate between local people and the Taliban," says Maj. Jim Gray with the British Army.

The aim of this operation is to regain control of an important town and restore security so rebuilding can begin — something the lack of security has so far prevented.

Counting forces from other NATO countries, there are now 47,000 foreign troops — more than half of them American. The U.S. alone has pumped in an additional 5,000 troops to aid the government of President Hamid Karzai in its battle against the Taliban, CBS News national security correspondent David Martin reports.

"I wanted to make sure that with our focus on Iraq that we didn't take our eye off the ball in Afghanistan, either," Secretary of Defense Robert Gates says.

One of the two aircraft carriers that had been sent to the Persian Gulf as a warning to Iran has now left the Gulf and is flying missions in support of the spring offensive, Martin reports. Compared to what the Taliban have to fight with, it might look like no contest, but Afghanistan is a war with no end in sight.

Unless the Taliban are defeated, everything the U.S., British and other NATO forces have achieved there is under threat, along with the stability of the Afghan government.