Trump would not be first president to secure release of U.S. prisoners from North Korea

President Trump's administration said that three U.S. prisoners held by North Korea may soon be released and that his policies have succeeded where previous administrations failed.

But past U.S. presidents have won the release of prisoners from North Korea, and the regime in Pyongyang routinely uses detainees as bargaining chips.

"This is a pretty regular thing," said Jeffrey Lewis, an analyst at the Middlebury Institute of International Studies. "North Korea grabs people and ransoms them when things get better."

In 2009, Kim Jong Un's father, Kim Jong Il, pardoned and released two American detainees when former president Bill Clinton visited Pyongyang as part of a high level U.S. delegation sanctioned by the Obama administration. The two women flew back to the United States with Clinton and his delegation.

Kim has not released the three current U.S. detainees, and there has been no official announcement from Pyongyang about it. But Rudy Giuliani, the former New York mayor now on Trump's legal team, said a release is imminent.

“We got Kim Jong Un impressed enough to be releasing three prisoners today,” Giuliani, told Fox & Friends on Thursday.

On Wednesday Trump tweeted, "As everybody is aware, the past Administration has long been asking for three hostages to be released from a North Korean Labor camp, but to no avail. Stay tuned!"

He didn't mention that two of the three people held by North Korea were imprisoned last year during Trump's presidency.

North Korea has a history of kidnapping people outside its borders and jailing foreigners who visit the isolated country.

An exception was Otto Warmbier, a college student accused of trying to steal a propaganda poster. He was released last year and died shortly after returning home.

His release did not appear to be part of a larger diplomatic overture and may have been related to his poor health.

Two Americans were released in 2014 after a secret mission by James Clapper, Obama's director of national intelligence.

North Korea has repeatedly shifted from bellicose threats and violent confrontations to peaceful gestures. "North Korea used this approach many times before," said Balazs Szalontai, an associate professor at Korea University.

Kim has seized the diplomatic initiative since agreeing to meet with Trump in a summit expected to be held in the coming weeks.

The news of a possible prisoner release followed an earlier pledge by Kim to shut a nuclear test site this month and allow journalists and others to watch it get dismantled. He also agreed to halt testing of intercontinental ballistic missiles and nuclear bombs.

Analysts are skeptical that Trump's earlier threats of military action were a primary reason for North Korea's diplomatic shift, though it might have contributed to the timing of Kim's move.

"I don't think that Trump's military threats have made any direct impact on the behavior of the North Korean leadership," Szalontai said.

More: Giuliani says 3 Americans held by North Korea will be freed today

More: Meet the three American prisoners being held by North Korea

More likely Kim's diplomatic offensive was triggered by a variety of factors, including pressure from economic sanctions, fears of a U.S. strike and perhaps the most critical — Kim’s confidence that his nuclear program is already a credible threat, analysts say.

North Korea was able to test its ICBMs and a thermonuclear weapon before Kim agreed to suspend the tests. Those were key objectives for the regime, Lewis said.

Kim may not have achieved as much as he would like. North Korea has missiles that can reach U.S. cities, but they remain unreliable and their accuracy is in doubt.

Kim may have decided that it was worth preserving what he had rather than risk a pre-emptive U.S. strike.

Trump's economic pressure on China in particular may have helped persuade Kim to move toward diplomacy, Szalontai said.

"By 2016-2017, the North Korean economy has become so dependent on China and so isolated from other partners that the overall effect of the new (U.N.-sponsored) sanctions relied almost exclusively on the extent of China's goodwill," Szalontai said.