The 101st Airborne Division ("Screaming Eagles") is a light infantry division of the United States Army specializing in air assault operations. The Screaming Eagles were referred to as "the tip of the spear" by former U.S. Secretary of Defense Robert Gates and the most potent and tactically mobile of the U.S. Army's divisions by former Chief of Staff of the Army GEN Edward C. Meyer (ret). The 101st Airborne is able to plan, coordinate, and execute brigade-size air assault operations capable of seizing key terrain in support of operational objectives and is capable of working in austere environments with limited or degraded infrastructure. These operations can be conducted by mobile teams covering large distances and engaging enemy forces behind enemy lines. According to the author of Screaming Eagles: 101st Airborne Division, its unique battlefield mobility and high level of training have kept it in the vanguard of US land combat forces in recent conflicts. More recently, the 101st Airborne has been performing foreign internal defense and counterterrorism operations within Iraq and Afghanistan