FACTBOX: Military policies of presidential candidates

(Reuters) - Following are the policies of the two main U.S. presidential candidates, Republican Sen. John McCain of Arizona and Democratic Sen. Barack Obama of Illinois, on major military and defense issues.

IRAQ

McCain broadly favors Bush administration policy -- withdrawing forces as commanders say it is safe to do so and as security improves. He has suggested the Iraq war would be won by the end of a first McCain presidential term in January 2013 and most U.S. troops would have returned home.

Obama says his goal is to remove all U.S. combat forces within 16 months of taking office. But he has also said he would leave a "residual force" to train Iraqi forces, conduct counter-terrorism operations and protect U.S. diplomats.

AFGHANISTAN

Obama argues that the war in Afghanistan is more important than Iraq and he has pledged to deploy at least two more combat brigades -- probably around 7,000 troops.

McCain has said commanders should get the three brigades they have asked for in Afghanistan but his emphasis on the Iraq war means it is possible those extra troops could take longer to arrive.

Both McCain and Obama have also called on NATO allies to deploy more troops and equipment to Afghanistan.

MISSILE DEFENSE

Advisers to McCain and Obama say both support systems to protect the United States from missile attack by nations such as Iran and North Korea.

McCain has been more wholehearted in his support while the Obama campaign says missile defense programs would face closer scrutiny than was the case under President George W. Bush.

SIZE OF U.S. MILITARY

Both McCain and Obama support a program begun under Bush to expand the U.S. Army and Marine Corps to a combined strength of some 750,000 active duty troops. McCain favors going further, with up to 900,000 personnel.

Neither candidate backs introducing a draft.

DEFENSE SPENDING

Both campaigns have said they do not see any prospect of reducing overall U.S. defense spending, at least in the short term.