MELBOURNE, Australia — At a news conference in New York on Monday, North Korea’s foreign minister accused U.S. President Donald Trump of declaring war via Twitter, and the minister threatened to shoot down U.S. Air Force bombers conducting flights near the Korean Peninsula.

Ri Yong Ho told reporters that his country “reserves the right to shoot down United States strategic bombers even when they’re not yet inside the airspace border of our country.” His comments come in the wake of a war of words between both countries over North Korea’s ballistic missile and nuclear weapons program.

The conference came after a Sept. 23 flight over international waters “east of North Korea” by U.S. Air Force B-1B Lancer bombers, escorted by F-15C jets, that U.S. Pacific Command said was the “farthest north of the Demilitarized Zone (DMZ) any U.S. fighter or bomber aircraft have flown off North Korea’s coast in the 21st century.”

According to South Korean media citing sources from the country’s intelligence services, the route of the B-1Bs took them approximately 90 miles from the North Korean port city of Sinpo and the Punggye-ri nuclear test site at its closest point but beyond the range of known long-range, ground-based air defense systems. The bombers’ flight path was also well beyond the North’s self-declared, 50-mile military boundary zone, which is not recognized by the United States.

At these distances, it would be a significant challenge for the North to effectively target any U.S. overflights. Like much of its conventional forces, North Korea’s air defense network is large in quantity but of questionable quality due to obsolescence, as the country is barred from importing military capabilities due to a United Nations arms embargo.

The Korean People’s Army Air Force operates one regiment each of the Soviet-era Mikoyan-Gurevich MiG-23 and MiG-29 interceptors as the leading edge of its air combat arm. Numbering about 30 aircraft of each type, these date from the late 1970s to early 1980s and are not believed to have received significant upgrades since delivery to North Korea.

Both types are typically deployed at bases near the capital Pyongyang close to the country’s reclusive leadership, although the country has been known to deploy fighter detachments to other bases as and when needed, with detachments noted at bases near the Demilitarized Zone with South Korea around the time of both the sinking of a South Korean naval corvette and the shelling of a South Korean island by North Korea in 2010.

CNN, citing U.S. defense officials, reported this week that “a small number” of MiGs have been deployed to a base on North Korea’s east coast, most likely Wonsan, along with external fuel tanks to increase their flight times along with air-to-air missiles. Such a move would enable North Koreans to respond faster should it choose to respond to another overflight off the coast, as it has previously done when MiG-23s and MiG-29s intercepted a U.S. Air Force RC-135 reconnaissance aircraft 150 miles offshore in 2003.

However, an attempted air intercept by North Korea is unlikely to succeed, particularly if U.S. Air Force bombers are backed by airborne early-warning aircraft orbiting out of range of the North Koreans and/or are escorted by friendly fighter jets. The North’s MiGs, which are used to operating along Soviet lines assisted by tight ground control, will be at a disadvantage when carrying out operations away from the coast.

This leaves the best chance of an attempted shootdown being through its surface-to-air missile, or SAM, network. The longest-range SAM in North Korea‘s inventory is the Russian NPO Almaz S-200, more commonly known in the West as the SA-5 Gammon. The S-200 is a 1960s Soviet system used to target high-flying, less-maneuverable aircraft with its large, radar-guided missiles. It has a maximum range of 150 or 250 miles, depending on the missile sub-variant.

The S-200’s size means it operates from fixed sites, with at least two such locations having been identified in North Korea, south and east of Pyongyang, covering the west coast and east coast respectively. North Korea is believed to operate four batteries of S-200s delivered in 1987 or 1988, which would equate to 24 launchers; although South Korean media has claimed the North may possess up to 40 launchers.

The system is a known quantity as far as its electronics and flight characteristics are concerned. It has been fired in anger by Libya in the 1980s and again by Syria earlier this year, and has not managed to hit its intended targets. The system is unlikely to be effective in an environment rich with electronic countermeasures, and the large missile will not be agile enough against a maneuvering target at the extreme end of its range.

North Korea has also recently shown off a new indigenous long-range SAM system known as the KN-06. This truck-mounted system looks broadly similar visually and dimensionally to the Russian S-300 or Chinese HQ-9 long-range SAMs, being vertically cold-launched from cylindrical missile tubes and guided by a phased array radar that bears some resemblance to the S-300’s 30N6 radar.

Little else is known publicly about the KN-06’s performance or effectiveness, although North Korea claims it has a range of almost 100 miles. State media has reported that North Korean leader Kim Jong Un has given the go-ahead for the system to be mass produced following several test launches, although sources have claimed that no known hits were scored during the tests.

North Korea has had form with shooting down U.S. military aircraft since the end of the Korean War in 1953 (although the Korean Peninsula remains in a technical state of war). It shot down a U.S. Navy EC-121 intelligence-gathering aircraft over international waters in 1969, and a U.S. Army OH-58 helicopter that accidentally strayed across the DMZ in 1994. However, the North’s ability to do so in 2017 is questionable.

It should be noted, however, that North Korea has shown an ability to bide its time for an opportune moment before striking, such as its sinking of the South Korean corvette in March 2010, a full six months after a naval clash with the South that led to several North Korean sailors being killed or injured.

Mike Yeo is the Asia correspondent for Defense News.

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