Tom Bowman

For the fourth time in six years, Obama introduced the man he wants to be secretary of defense. Ashton Carter, a Pentagon veteran, is Obama's nominee to replace Chuck Hagel.

Defense Secretary Chuck Hagel announced his resignation on Monday. He will stay on until his replacement is found. Why did Hagel resign, and what does it mean for the Obama administration's policies?

About 100 female Marines are taking part in a year-long experiment to determine whether they have what it takes to serve in ground combat units: infantry, armor and artillery. Some of...

Chuck Hagel's resignation comes amid concern over the rise of ISIS, also known as the Islamic State, and a return of U.S. troops to Iraq. President Obama is announcing the move Monday morning.

The Marine Corps has begun a yearlong experiment to decide whether women can enter ground combat. Hundreds of men and women began training a few weeks ago at Camp Lejeune in North Carolina.

The White House authorized the deployment an additional 1,500 U.S. military personnel to Iraq to help advise that country in its fight against the so-called Islamic State, or ISIS.

President Obama awarded the Medal of Honor on Thursday to a soldier who stayed at his post under withering fire, 150 years ago. Lt. Alonzo Cushing was just 22, commanding an artillery...

U.S. airstrikes against the Islamic State began nearly three months ago, yet there have been relatively few changes on the battlefield. Many analysts say the U.S. effort may not be sufficient.

Army Chief of Staff Gen. Ray Odierno announced that all soldiers going to the Ebola region in West Africa would go through three weeks of monitoring, even though the soldiers will not...

Militants from the Islamic State, also known as ISIS, control about 80 percent of Iraq's Anbar Province. Joint Chiefs Chairman General Martin Dempsey says ISIS could eventually shell Baghdad Airport.

The Obama administration's strategy against ISIS is fraying, according to U.S. officials. The bombing strikes are too small and dispersed, leading to a charge that they are "Shock and...

There have been about 400 airstrikes so far in Iraq and Syria. We take a look at the impact in both countries, whether the Islamic State fighters have been slowed, and the way ahead.

Despite President Obama's assertion that the combat mission in Afghanistan would be over by the end of 2014, the new agreement means that 10,000 U.S. troops will still be in harm's way.

The U.S. launched another round of airstrikes inside Syria on Wednesday, again targeting the group known as the Islamic State.

The U.S., along with several Arab states, launched air strikes inside Syria overnight. The strikes targeted the group that calls itself the Islamic State.

The U.S. and its allies expanded the assault against the Islamic State. The Pentagon says targets inside Syria were hit for the first time. The attacks are focused on ISIS assets around Raqqa.

The Obama administration says that American advisers sent to Iraq will not have a combat mission. But military experts say it's almost impossible to draw a line between combat and non-combat roles.

Secretary of Defense Chuck Hagel and Gen. Martin Dempsey, the chairman of the Joint Chiefs of Staff, testified before a Senate committee on Tuesday.

The U.S. has secured commitments from some Arab nations and allies to cooperate in the battle against the militant group known as the Islamic State.

President Obama will send 475 additional troops to Iraq to train, assist and advise Iraqi forces on the fight against militants in the Islamic State. But they will not be involved in combat.