APPresident Obama announcing the replacement of General McChrystal with General David Petraeus

The president says the change is not a change in policy. He says General Petraeus understands that strategy because he helped shape it.

General Petraeus is known for his political as well as military skills. Experts credit him with a successful counterinsurgency strategy in Iraq in two thousand seven and two thousand eight. Counterinsurgency involves military action but also depends on civilian relationships to succeed.

The Afghanistan policy calls for establishing security in cities and towns, protecting civilians even if it means more danger for coalition troops. It also involves training local security forces and strengthening the government.

Last month, General Petraeus talked about the situation.

DAVID PETRAEUS: "As was the case in Iraq, the reality is that everything in Afghanistan is hard. It's hard all the time, and it typically gets harder before it gets easier."

General McChrystal was one of the relatively few American officials to develop a good relationship with Afghan President Hamid Karzai. But he never did the same with the American ambassador, Karl Eikenberry, a former commander in Afghanistan.

On Wednesday, President Obama repeated the policy agreed to last fall.

BARACK OBAMA: "We are going to break the Taliban's momentum. We are going to build Afghan capacity. We are going to relentlessly apply pressure on al-Qaida and its leadership, strengthening the ability of both Afghanistan and Pakistan to do the same."