BBC correspondent Jonny Dymond has been to two US camps in Iraq's Diyala province, where troops are battling insurgents driven out of other parts of the country. He and cameraman Bhas Solanki joined the troops on patrol.
CLEARING HOUSES OF ARMS
Until recently Baquba, the provincial capital of Diyala, was held by the Sunni militant group al-Qaeda in Iraq.
The US military have broken their hold and are now clearing houses of arms caches and supporting both the Iraqi army and the Sunni militia - known to the US military as Concerned Local Citizens - in their attempts to hold the city.
US soldiers make regular patrols - partly to show the local population that al-Qaeda in Iraq has gone, partly to maintain a flow of tips and information, and partly to ensure that insurgents cannot re-establish bases in the city.
There are many abandoned houses and these are used by insurgents to store arms.
Here, Sergeant Aaron Jackson, of 1st Platoon, Bravo Company 1-38 2nd Infantry explains how they clear houses - and watch for booby-traps.
ALL IN A DAY'S WORK
Sometimes it is the offbeat episodes that give the best insights into daily difficulties.
I was relaxing after a long day with the US military and looking forward to a hot meal when things started to go wrong. Nobody attacked the convoy and no bombs went off.
Instead it was dark roads and either lousy driving or treacherous conditions that led to a five-hour extension to my day into the cold muddy night. But it was worth every minute of the discomfort, for the insights into the people I'd spent the day with.
THE MANY ROLES OF A US SOLDIER
Some of the fiercest fighting in Diyala took place in what was once known as "the breadbasket" - a rich agricultural area in the heart of the province.
Now US forces have re-established control, but they're still working to build up both the Iraqi army and police presence and to bring the local population - mainly Sunni in this area - on side.
At the same time there is a continuing threat from militants operating in the area.
This means that American soldiers have to perform a myriad of different jobs - diplomats, negotiators, search teams, paramilitary police, to name but a few.
Here, Lt Col Rod Coffee explains what he sees when he visits his men and what lies behind the current strategy.