Today, General Lloyd Austin became the first African-American to lead the U.S. Central Command, which has a wide-ranging area of responsibility for 20 countries in the Middle East and southwest Asia. His appointment is effective immediately. During the change of command ceremony today, Secretary of Defense Chuck Hagel said, "General Austin brings to this position combat experience gained on the unforgiving battlefields of Iraq and Afghanistan. He has commanded some of the Army's most storied formations, including the 82nd Airborne and 10th Mountain Divisions, as well as the 18th Airborne Corps... With his calm demeanor, strategic vision, regional experience and knowledge, and proven judgment -- and with the love and support of Charlene and their children -- I am confident General Austin is prepared to lead this command at a time of dramatic change, challenge, and turmoil in its area of responsibility." In his 37-year career, General Austin has continually broken barriers for African-Americans in the U.S. Army. He was also the first African-American to serve in his previous position as the Vice Chief of Staff of the Army. His historic career includes leading the 3rd Infantry Division in the opening months of the Iraq war where he earned a Silver Star for valor. General Austin later commanded divisions in both Afghanistan and Iraq, and commanded U.S. Forces-Iraq from September 2010 through the completion of the mission in December 2011. In a statement last December, then-Secretary of Defense Leon Panetta said, "During his final deployment to Iraq, Gen. Austin led our military efforts at a particularly important time, overseeing the drawdown of U.S. forces and equipment while simultaneously helping to ensure that hard-fought security gains were preserved and that Iraqis could secure and govern themselves. Lloyd would bring an important combination of strategic thinking, regional knowledge and proven judgment to one of the most critical posts in the department." General Austin introduced President Obama when he spoke to soldiers at Fort Bliss last August. In his remarks, President Obama acknowledged General Austin's extraordinary leadership in Iraq, overseeing the withdrawal of 150,000 troops. General Austin succeeds Marine Corps General James Mattis. We thank General James Mattis for his leadership, and look forward to General Austin's continued service to our country in this new role. We are incredibly grateful to both of them, and to all of our men and women in uniform, for keeping our country safe and our freedoms secure. Valerie Jarrett is a senior adviser to President Barack Obama and Assistant to the President for Public Engagement and Intergovernmental Affairs.