Seoul:
The Cold War still rages in North Korea, and enemy No. 1 is the United States, which Pyongyang blames for making its much-condemned drive to develop nuclear weapons necessary.
A rich vein of propaganda fueled by decades-old American threats holds that North Korea remains at risk of an unprovoked nuclear attack, though Washington and others say brinksmanship is the North's true motive.
North Korea's latest nuclear test in February - its third - has led even China, its only major ally, to support another round of punishing U.N. Security Council sanctions. Washington and Beijing have approved a draft resolution that is expected to be circulated this week.
North Korea's neighbors and the West condemn the North's efforts to develop nuclear missiles capable of hitting America as a serious threat to Northeast Asia's delicate security and a drain on the precious resources that could go to North Korea's largely destitute people.
But in Pyongyang, the propaganda spotlight shines on a long list of perceived wrongs from Washington and, in particular, on high-level American nuclear threats from the 1950s to the 1970s.
The United States removed its atomic bombs from South Korea in 1991 and has repeatedly rejected North Korea's claims of U.S. invasion plans. U.S. nuclear submarines ply the region's waters, however, and Washington makes clear that its so-called nuclear "umbrella" over South Korea is meant to deter an attack on its ally by North Korea, whose 1950 invasion ignited the three-year Korean War.
Pyongyang uses Cold War history with the U.S. to justify nuclear weapons as a necessity for a small, proud country wedged among global powers competing for regional economic, military and political supremacy.
"No nation has directly been exposed to the U.S. nuclear threat for such a long time in the world," a recent - and representative - commentary from the North's official Korean Central News Agency said.
Faced with Washington's "ceaseless nuclear blackmail and sanctions racket," the commentary said, North Korea made "the strategic resolution to react to nuclear weapons with nuclear weapons."
This is widely dismissed by outsiders as a rationalization. U.S. officials say North Korea orchestrated a systematic, often secret drive to build bombs even while making nuclear disarmament pledges to Washington and others in return for aid and other concessions.
"North Korea uses these nuclear weapons every day. They haven't launched them, but they use them regularly," said Bruce Bennett, a defense analyst at the RAND Corporation, a U.S.-based think tank. Among the uses, he said: to "blackmail" and intimidate Washington and others for money and supplies; to agitate for a peace treaty to end the still technically ongoing Korean War; to deter possible attacks; to generate scapegoats meant to obscure government failures; and to allow the ruling Kim family to demonstrate power and stability to the world and to their citizens.
Pyongyang excoriates international sanctions as expressions of U.S. hostility, as it does joint U.S.-South Korean military drills, the 28,500 U.S. troops stationed in South Korea and the tens of thousands based in nearby Japan.
"There are good reasons for North Korea to fear the United States," said Cheong Seong-chang, a South Korean analyst at the private Sejong Institute think tank. "There's a sense of crisis that persists among North Koreans toward Washington, which deploys satellites around the clock to keep a watch on Pyongyang."
Those fears stretch back to the Korean War and the nuclear gamesmanship of the Cold War.
Gen. Douglas MacArthur, the U.N. forces commander, and his successor, Gen. Matthew Ridgway, both asked for authority to use atomic bombs against the North. After his 1953 inauguration, President Dwight Eisenhower "began dropping hints that the United States would use the atom bomb if the deadlock persisted in the negotiations to conclude an armistice ending the war," former Washington Post reporter Don Oberdorfer writes in his history "The Two Koreas."
The first openly deployed U.S. nuclear weapons appeared in South Korea in 1958, according to Peter Hayes, who heads the Nautilus Institute, an Asia-focused think tank, and North Korea responded by digging underground tunnels and fortifying the border.
A crucial moment came in August 1976, after North Korean soldiers killed two Americans with axes. An angry Washington looked to send a message, and nuclear-capable B-52 bombers flew toward the demilitarized zone separating the Koreas, "veering off at the last moment," Hayes wrote in his book "Pacific Powderkeg."
The U.S. response to the ax murders, according to Hayes, convinced North Korea that the American nuclear threat was real, and the psychological impression it made continues even now.
Recent North Korean propaganda has also focused on the George W. Bush and Obama administrations. In 2002, Bush lumped North Korea into an "an axis of evil" with Iran and Iraq. The U.S. invaded Iraq in 2003, and the Bush administration advocated "regime change" in Iran and, reportedly, in Pyongyang.
North Korea has also studied the fate of Libyan dictator Moammar Gadhafi, who gave up his nuclear programs in 2003 under U.S. economic pressure and was killed in 2011 in an uprising backed by NATO airstrikes.
Pyongyang's state media recently wrote of the "tragic consequences" of countries that "abandoned halfway their nuclear programs" because of U.S. pressure, adding that North Korea "was very far-sighted" when it decided to continue building nuclear arms.
North Korean fears of nuclear attack may seem ridiculous to Americans who see U.S. intentions as obviously defensive, according to Hayes, but the view is different in North Korea.
"Isolated from world opinion, subject to the vagaries of centralized, bureaucratic policy formation and the whim of extraordinarily concentrated political power, Pyongyang is the one place that probably does not see the world the same way as 'everyone' else," Hayes wrote.
Even if deadlocked nuclear disarmament negotiations resume, analysts see no easy solution to stopping North Korea's nuclear weapons drive.
Washington says North Korea must prove its sincerity before any serious disarmament deal can be reached. The Obama administration is focused on the North's own more recent history, which it considers to be rife with broken disarmament promises.