Most estimates suggest that North Korea has an unusually large number of armed forces personnel for its population of 25 million. The U.S. State Department has estimated that North Korea had more than 1.18 million armed forces personnel in 2014, making it the fourth-largest army in the world after China (2.37 million), India (1.41 million) and the United States (1.43 million).
For comparison, Iraq's military in 2003 was estimated to be have 445,000 men for a population of around 26 million people.
This massive standing army comes by design: North Korea's constitution explicitly states that “national defense is the supreme duty and honor of its citizens” and that citizens are required to serve in the armed forces by law. A 2015 congressional report from the Defense Department estimated that 4 percent to 5 percent of North Korea's citizens were on active military duty with the Korean People’s Army (KPA), while another 25 percent to 30 percent were assigned to a reserve or paramilitary unit and would be subject to wartime mobilization.
The effectiveness of such a force is not totally clear. Accounts from American soldiers who fought in the Korean War almost seven decades ago suggest that the North's solders were unusually good at evasion and determined to win. However, the Pentagon report states that the KPA primarily fields aging equipment based on technology as old as the 1950s, often produced or based on designs from the Soviet Union or China.
A Japanese filmmaker who runs a network of citizens journalists in North Korea claimed last month that due to the country's chronic food shortage much of the standing army was too weak to fight. “[One contact] told me that there was talk of war with the US, but that many North Korean soldiers are in poor physical condition and in no fit state to fight,” Jiro Ishimaru told the Guardian newspaper in August.
However, experts suggest that the forward-deployed army would still pose a threat to South Korea and its U.S. allies in a war. In any conflict, North Korea's well-trained special operations forces — estimated to number at least 180,000 military personnel — are widely expected to be used to attack key facilities in South Korea.
Along with the country's rapidly advancing missile program, its nuclear and biological weapons, and the enormous amount of artillery it has aimed at South Korea's capital, Pyongyang's exceptionally large standing army is yet another reason analysts are hesitant to recommend U.S. military action from North Korea, despite its leader's repeated threats.