U.S. military leaders voiced concern Wednesday about their ability to fight a conventional war against the armed forces of countries like China, Russia, Iran and North Korea.
U.S. Army Chief of Staff General Mark Milley told the House Armed Services Committee the military's anti-terrorism and counterinsurgency focus on the Middle East has taken resources away from planning and preparation to fight a "higher-end" combat force if a conflict erupted in another part of the world.
"If that were to happen, I would have grave concerns about the readiness of our force to deal with that in a timely manner," Milley said.
But while most of their readiness concerns were directed at potential conflicts with major powers Russia and China, they also come at a time of escalating tensions on the Korean peninsula over the North's nuclear threat.
U.S. and South Korean forces have increased their readiness defense posture following Pyongyang's nuclear test in January and long-range rocket launch in February.
Washington has moved more troops and assets into the region and the two allies are currently conducting their largest joint exercises ever, involving 17,000 American troops, 300,000 South Korean troops, and an array of U.S. aircraft and naval vessels.
North Korea has called these annual drills rehearsals for invasion and the country's supreme leader, Kim Jong Un, has threatened to conduct pre-emptive nuclear strikes against South Korean and the U.S. forces.
"Early on in the conflict the North Koreans have an enormous incentive to use missiles and artillery to strike as many U.S. forces in the region, I think first as a war winning measure in order to slow down the rate of which the United States can flood forces into South Korea and up to Pyongyang, but I think also in the hope that the casualties will cause the United States to back off," said Jeffrey Lewis, the director of the East Asia Nonproliferation Program at the Middlebury Institute of International Studies in California.
The slogan for the U.S. forces in Korea is "ready to fight tonight" and part of this year's exercises is preparing to counter the North's nuclear threat.
In addition to combat drills, the allied forces are also simulating surgical pre-emptive strikes against the North Korean leadership and the taking out of key military installations.
North vs. South
North Korea's military is listed as the 36th most powerful in the world, according to the website Global Firepower which evaluates the military capability of countries.
The North has an advantage over the South in some categories, with 700,000 active forces (and over 4 million in the military reserves), 4,200 tanks and 70 submarines.
But much of its conventional weaponry was built or designed by the Soviet Union in the 1950s.
South Korea is seventh in the Global Firepower world ranking, even though it has significantly fewer armed forces, half the number of tanks, and only 13 submarines.
However, South Korea has some of the best modern American weapons and equipment, including more than 2,000 tanks and hundreds of F-5, F-15 and F-16 fighter jets and fighter-bombers.
Together, the U.S. and South Korean militaries are widely considered to have superior conventional forces in the region that are better equipped, better trained and better fed than those in the impoverished North.
The North's answer to its conventional military disadvantage has been to develop nuclear weapons.
"North Korea's concentration on the development of nuclear power and missiles shows that it recognizes that it is far behind South Korea's conventional military capability," said analyst Kim Dong-yub, with Kyungnam University's Institute of Far Eastern Studies in Seoul.
There are currently close to 28,500 U.S. troops in South Korea. Since the end of the Korean War in 1953, the U.S. has maintained a military presence in South Korea to enforce the armistice agreement that divided the peninsula along the 38th parallel between the communist North and the capitalist South.
Source: Voice of America