North Korea has repeatedly pledged it would make peace and abandon its nuclear programs. Is this time different? Here's everything you need to know:

What is being proposed?

North Korean dictator Kim Jong Un has offered to remove all nuclear weapons from the Korean Peninsula in return for a permanent peace deal. At a historic meeting last month with South Korean President Moon Jae-in in the Demilitarized Zone that has divided North and South since the 1953 armistice, Kim agreed to negotiate a treaty to finally end the frozen conflict. "I came here to put an end to the history of confrontation," Kim said. It may or may not represent a change of policy: His family's secretive, Stalinist regime has a decades-long record of promising to halt its nuclear programs in exchange for sanctions relief or aid. Kim's father, Kim Jong Il, who came to power in 1994 after the death of his father, Kim Il Sung, agreed to end nuclear weapons or missile activities that year — and then again in 2000, 2005, and 2007. Each time, Pyongyang secretly continued its nuclear tests and missile development. The U.S., said then–Defense Secretary Robert Gates in 2009, is "tired of buying the same horse twice."

When did the programs start?

North Korea began trying in earnest to make a bomb in the 1990s, after the collapse of the Soviet Union, which had been a key ally. In 1993, North Korea threatened to withdraw from the Nuclear Non-Proliferation Treaty after the International Atomic Energy Agency found evidence that its nuclear plants were producing plutonium — bomb fuel. Alarmed, President Bill Clinton sought to cut off nuclear development by negotiating a sweeping deal with the Kim regime: the Agreed Framework. North Korea agreed to halt construction of its nuclear reactors in exchange for the U.S.'s building it two new ones that could not be altered to produce plutonium. But in 1998, Pyongyang began testing ballistic missiles. Negotiations over how to stop that program were ongoing when President George W. Bush took office.

What did Bush do?

He ordered a policy and intelligence review, which found that North Korea was secretly developing the capability to enrich uranium — another kind of bomb fuel. Bush cut off fuel oil shipments made under the Agreed Framework, and by 2002 North Korea had pulled out of all deals, saying the U.S. had violated their terms. The U.S. turned to North Korea's neighbors and allies for help. The resulting "six-party talks" among North and South Korea, the U.S., China, Russia, and Japan produced a new deal, with North Korea promising in 2005 to "abandon nuclear weapons and existing nuclear programs." Given Pyongyang's past cheating, Bush insisted on strict verification measures, but North Korea continued to stall on implementing them. In 2006, North Korea conducted its first underground nuclear test. By the time President Obama took office in 2009, North Korea had bomb capability, and the six-party process had broken down.

What did Obama do?

The Obama administration tightened sanctions while dangling the prospect of negotiations. In 2011, Kim Jong Il died and was succeeded by his son, Kim Jong Un. Just two months into the new regime, North Korea and the U.S. signed the "Leap Day" agreement on Feb. 29, 2012, which declared a moratorium on missile launches and nuclear tests. But the young Kim was focused on proving his toughness to his generals and to North Koreans, so he ignored that pledge and began testing nuclear bombs of greater magnitude. When President Trump took office with a threat to rain down "fire and fury" on North Korea, the regime simply redoubled its efforts, announcing breakthroughs in miniaturization of warheads and ballistic missile technology. Nine months after Trump took office, North Korea claimed to have tested a hydrogen bomb — a huge leap in destructive power. Two months later, it tested an ICBM, with the stated goal of delivering a nuclear attack on U.S. cities. But after an exchange of threats with Trump, in which the two leaders warned they could destroy each other's nations, Kim suddenly announced he was willing to negotiate directly with the U.S. president.

Is anything different this time?

Yes. For the first time, Pyongyang has both nuclear weapons and intercontinental ballistic missiles that can reach the U.S., so it is negotiating from a much stronger position. At the same time, the much tougher international sanctions the Trump administration has imposed have badly hurt North Korea's already weak economy. Trump administration officials are cautiously optimistic that since Kim's overriding goal is to preserve his regime, he might trade his weapons for a peace treaty that provided sanctions relief and strong guarantees that the U.S. would not attack North Korea. Skeptics, however, think Kim is just buying time until he completes the final step in becoming a nuclear power: creating a warhead small enough to fit on an ICBM and sturdy enough to withstand re-entry into the atmosphere. Still, President Trump is confident. "The United States has been played beautifully, like a fiddle, because you had a different kind of a leader," Trump said. "We're not going to be played, OK?"

Why the U.S. is the enemy

North Korea blames the U.S. for dividing it from South Korea along the 38th parallel after World War II. And it has bitter memories of the 1950 U.S. invasion, when American planes burned villages with napalm and U.S. tanks and troops pushed North Korean forces nearly to the Chinese border. As many as 4 million Koreans died in the fierce fighting and bombing, including an estimated 25 percent of the North's population. "North Korea was flattened," said University of Chicago historian Bruce Cumings. "The North Koreans see the American bombing as a holocaust, and every child is taught about it." Ever since, hatred of the U.S. has been a cornerstone of North Korean identity. The regime is organized around the massive military — 1 million strong in a country of 25 million — whose explicit goal is to prevent U.S. invasion at any cost. Anti-U.S. propaganda is a constant, and "Struggle Against U.S. Imperialism Month" is observed every year.