Democrats and Republicans have been quick to use North Korea’s apparent nuclear test to benefit their own party in these final weeks of the congressional campaign, but a review of history shows that both sides have contributed to the current situation.

There is more than 50 years of history to Pyongyang’s attempt to gain a nuclear weapon, triggered in part by threats from Presidents Harry S. Truman and Dwight D. Eisenhower to end the Korean War.

In 1950, when a reporter asked Truman whether he would use atomic bombs at a time when the war was going badly, the president said, “That includes every weapon we have.”

Three years later, Eisenhower made a veiled threat, saying he would “remove all restraints in our use of weapons” if the North Korean government did not negotiate in good faith an ending to that bloody war.

In 1957, the United States placed nuclear-tipped Matador missiles in South Korea, to be followed in later years, under both Republican and Democratic administrations, by nuclear artillery, most of which was placed within miles of the demilitarized zone.

It was not until President Jimmy Carter’s administration, in the late 1970s, that the first steps were taken to remove some of the hundreds of nuclear weapons that the United States maintained in South Korea, a process that was not completed until 1991, under the first Bush administration.

It is against that background that the North Korean nuclear program developed.

North Korea has its own uranium mines and in 1965 obtained a small research reactor from the Soviet Union, which it located at Yongbyon. By the mid-1970s, North Korean technicians had increased the capability of that reactor and constructed a second one. Pyongyang agreed in 1977 to allow the International Atomic Energy Agency (IAEA) to inspect the first reactor.

It was in the 1980s that the North Korean weapons program began its clandestine growth with the building of a facility for reprocessing fuel into weapons-grade material and the testing of chemical high explosives. In 1985, around the time U.S. intelligence discovered a third, once-secret reactor, North Korea agreed to sign the Nuclear Non-Proliferation Treaty (NPT).

Five years later, U.S. intelligence discovered through satellite photos that a structure had been built that appeared to be capable of separating plutonium from nuclear fuel rods. Under pressure, North Korea signed a safeguards agreement with the IAEA in 1992, and inspections of facilities began. But in January 1993, IAEA inspectors were prevented from going to two previously unreported facilities. In the resulting crisis, North Korea attempted to withdraw from the NPT.

The Clinton administration responded in 1994 that if North Korea reprocessed plutonium from fuel rods, it would be crossing a “red line” that could trigger military action. The North Koreans “suspended” their withdrawal from the NPT, and bilateral talks with the Clinton administration got underway. When negotiations deadlocked, North Korea removed fuel rods from one of its reactors, a step that brought Carter back into the picture as a negotiator.

The resulting talks led to the 1994 Agreed Framework, under which North Korea would freeze and eventually dismantle its nuclear weapons program. In return, it would be supplied with conventional fuel and ultimately with two light-water reactors that could not produce potential weapons-grade fuel.

However, a subsequent IAEA inspection determined that North Korea had clandestinely extracted about 24 kilograms of plutonium from its fuel rods, and U.S. intelligence reported that was enough material for two or three 20-kiloton plutonium bombs.

During the next six years of the Clinton administration and into the first years of the current Bush administration, the spent fuel from North Korea’s reactors was kept in a storage pond under IAEA supervision. As late as July 5, 2002, in a letter to Rep. Edward J. Markey (D-Mass.), then-national security adviser Condoleezza Rice said the administration was continuing with the 1994 agreement but holding back some elements until the IAEA certified that the North Koreans had come into full compliance with the NPT’s safeguards agreement.

In November 2001, when the Bush administration was absorbed in the aftermath of the Sept. 11 terrorist attacks, intelligence analysts at the Lawrence Livermore National Laboratory completed a highly classified report that concluded North Korea had begun construction of a plant to enrich uranium. A National Intelligence Estimate of the North Korean program confirmed the Livermore report, providing evidence that Pyongyang was violating the agreement.

Nonetheless, the Bush administration waited until October 2002 before confronting the North Koreans, who at one meeting confirmed they were following another path to a nuclear weapon using enriched uranium.

Soon thereafter, the United States ended its participation in the 1994 agreement. North Korea ordered IAEA inspectors out, announced it would reprocess the stored fuel rods and withdrew from the NPT. Earlier this year, Pyongyang declared it had nuclear weapons.

The Bush administration then embarked on a new approach, developing a six-nation strategy based on the idea that bilateral U.S.-North Korea negotiations did not work and that only bringing in China and South Korea, which had direct leverage over the Pyongyang government, would gain results.

First Published in the Washington Post