The Pentagon has extended the tours of about 3,500 US troops in Iraq for 120 days in a move that dashed hopes of a reduction in the US force this year in the face of surging sectarian violence. The Pentagon also identified four other brigades with 25,000 troops for deployment to Iraq late this year and early next, enough to maintain the US force at about 130,000 troops for a year. "Additionally, the Secretary of Defence approved a request by the commander of Multi-National Forces-Iraq (MNF-I) to extend the deployment of the 172nd Stryker Brigade Combat Team operating in Iraq...