On Sunday, President Trump tweeted that the lack of nuclear missiles on display during North Korea’s Foundation Day parade was a good sign adding, “There is nothing like good dialogue from two people that like each other!”

Setting aside the obvious problems with the president of the United States “liking” the North Korean dictator responsible for enslaving his own people and threatening the world with nuclear weapons, Trump’s claims to historic progress on a nuclear deal are impossibly naive and display historical ignorance. Here’s a look at past attempts at deals and their lessons:

In the 1980s, North Korea began seriously working towards nuclear capacity supported by the Soviet Union. It built its first nuclear power plant, Yongbyon, although it insisted that it was not for military purposes. Trying to add credibility, it signed the Nuclear Nonproliferation Treaty in 1985 and an additional agreement with South Korea in 1991 saying that neither country would produce or use nuclear weapons.

[John Bolton: Trump 'can't make' North Korea denuclearize]

Yet, when the International Atomic Energy Agency wanted to test North Korea’s nuclear waste sites, the North threatened to leave its previous agreements.

This should have been Trump’s first lesson: Agreements must be verifiable.

In 1994, under the Clinton administration, North Korea said it could reprocess fuel rods to build up to six nuclear weapons. Weighing options, including a strike against the nuclear plant, the Clinton administration decided to pursue negotiations which led to the Agreed Framework. North Korea agreed to halt production and eventually dismantle its nuclear facilities.

At first, this seemed to work: North Korea’s reactor shut down, a missile test failed, and North Korea kept talking, even agreeing to not test medium- and long-range missiles while talks were ongoing.

George W. Bush’s administration, however, was far more skeptical of North Korea’s commitment to upholding the Agreed Framework. Talks were postponed, and Bush called North Korea an axis of evil. Then, in 2002, the administration said that North Korea was secretly enriching uranium.

In January 2003, North Korea left the Nonproliferation Treaty, the Agreed Framework fell apart, and, a few months later, the U.S. reported that North Korea said that it had admitted to producing a nuclear weapon.

Here is the second lesson: North Korea may well commit to getting rid of its weapons, but it will remain skeptical of the U.S., leading to incentives to keep, or, in this case, produce, nuclear weapons.

Bush tried to re-engage with North Korea in 2003 with the Six Party Talks including South Korea, Japan, Russia, and China. In 2005, the talks resulted in another agreement for North Korea to give up its nuclear weapons. It was also supposed to rejoin the Nonproliferation Treaty and accept inspections of its nuclear sites.

Clearly, that agreement fell apart too. By July 2006, North Korea had tested seven ballistic missiles, in violation of its 1999 agreement. And, in October, North Korea tested its first nuclear weapon.

Here’s the third lesson: Look at what North Korea is doing, not what it is telling U.S. negotiators.

Under Obama, North Korea tested a new rocket and faced new sanctions. In response, it backed out of agreements from the previous Six Party Talks and kicked inspectors out of the country. In 2009, North Korea tested another, larger, nuclear weapon leading to a new round of sanctions.

Feeling pressure in 2011, Pyongyang wanted new talks. This interest didn’t bear fruit, however, as longtime dictator Kim Jong Il died suddenly leaving his son Kim Jong Un in power.

Since then, despite a 2012 agreement to not test nuclear and long-range missiles, the country again attempted to launch new missiles, triggering additional sanctions. Although previous attempts had failed, in December 2012, the country successfully launched a rocket into orbit triggering even more sanctions.

In recent years, North Korea has sped up the pace of its tests, including three more nuclear tests as well as the development of its missile program.

In July 2017, North Korea successfully test fired an intercontinental ballistic missile that could hit Alaska and completed its most powerful nuclear test yet — which North Korea claims was a hydrogen bomb.

Then, Kim Jong Un reached out to Trump and asked for new talks on the country’s nuclear program. In April, North Korea said it would quit testing nuclear weapons and missiles. In June, Trump and Kim Jong Un met in Singapore and signed yet another statement in which the North indicated willingness to give up its weapons.

Since then, Trump has championed incremental success in negotiating with the North despite indications that North Korea has no intention of giving up its weapons and has, instead, continued production and worked to conceal its activities.

This fourth lesson, which Trump, like presidents before him, seems to have had to learn for himself: an agreement with North Korea does not mean the country will give up its weapons.

On North Korea negotiations, Trump jumped in headfirst, moving quickly and without heed for warnings from seasoned advisers. They all saw what Trump, in his eagerness to get a deal, did not: North Korea isn’t easily going give up its nuclear weapons. Perhaps now, with these lessons, which Trump could and should have learned from his predecessors, but was instead taught by his own experience, he will be better prepared to actually make progress on North Korea.

His latest tweets, however, in light of history, do not instill confidence.