Marjah Marines Begin Taliban Battle

Marines on the outskirts of Marjah, a Taliban stronghold in Afghanistan, before a new offensive.

CBS News has learned that the operation to take control of Marjah, the last major Taliban holdout in Helmand province has just started. CBS News correspondent Mandy Clark spent all week with the Marines as they prepared for the battle.

In the no-man's land surrounding Marjah, Marines check it before they cross to make sure it hasn't been booby trapped. Armored vehicles called "breachers" are sent in first. These mine-clearing machines spread out a string of explosives and set them off, detonating any other bombs the Taliban may have placed along this route.

Major Offensive against Taliban Begins

The Marines have had the enemy in their sights for days and occasionally they have exchanged fire. They know that they are about to enter a very dangerous city.

The military believes around 400 to a 1,000 hard-core Taliban fighters are holed up inside Marjah and they've had plenty of time to prepare for the fight, so the coalition is going in with overwhelming force. Thousands of Allied and Afghan troops have Marjah surrounded and these Marines are going to be leading the charge. Their commander says they're ready.

"They have a great battle plan and those leaders all the way from the NCO to the young captain will defiantly make a difference and we'll definitely be successful," said Lt. Col. Brian Christmas.

But winning the battle is only the first step. The key to victory here is to maintain control of the city for the long term, which is why the Marines are already reaching out to the local population.

"If you know where the Taliban are, you need to tell us," Christmas told local elders.

Getting the cooperation of the local leaders has taken longer than expected, but it is a key component of the new military strategy known as "clear, hold, build.'' The Marines are here to do the clearing, but it will be up to the Afghans to do the holding and the building.

It's been a long wait for these Marines. But now the time for battle has finally come.