...at Iran's main uranium enrichment complex near the city of Natanz, a small team of international inspectors studies information transmitted around the clock by surveillance cameras, online monitors and fiber-optic seals on nuclear equipment.
The International Atomic Energy Agency describes the transcontinental monitoring program it operates as the toughest and most technologically advanced inspections regime put in place to prevent a country from developing an atomic bomb.
source: The LA Times -
http://www.latimes.com/world/middleeast/la-fg-iran-inspections-2017-story.html
Trump then claimed after being proven wrong (yet again) about their compliance that it wasn't doing anything about their other military programs. Those were never part of the deal to begin with. In other words, Trump pulled out of the deal and once again moved towards war for no other reason than he wanted to.
As part of the terms imposed on a defeated Iraq in 1991, the UN Security Council had ordered Iraq to destroy or render harmless all its weapons of mass destruction (WMDs), under UN supervision. Inspectors had gone in, and large quantities of WMDs were destroyed. In March 1995, the Iraqi government delivered its “Full, Final and Complete Disclosure” of all its weapons, and demanded in return an end to sanctions imposed after the Gulf War.
After the Crawford summit, British intelligence and the diplomatic corps knew what they had to do - they had to persuade the UN Security Council to issue an ultimatum that put the onus on Saddam Hussein to prove that his country held no WMDs, with the implied threat that if he failed, military action would follow.
The diplomatic half of this mission was a startling success. On 8 November 2002, the UN Security Council unanimously adopted Resolution 1441, which gave the Iraq government “a final opportunity to comply with its disarmament obligations.” Though it did not specify what would happen if Iraq failed to comply, or who would make that judgement, getting the resolution adopted was all the same a considerable achievement.
The problems were in the other half of the mission, when it came to producing evidence that Iraq still held WMDs. This takes us into one of the most contentious questions of the whole Iraq debacle - did Tony Blair lie when he claimed that there were WMDs still in Iraq? Over the years, the suspicion that he did has hardened into certainty.
But just as the Prime Minister could not know for certain that there were no WMDs left in Iraq, neither could he have known that there were any. He was not lying. He was presenting to Parliament a series of guesses made by the intelligence services - but he dressed them up as if they were hard facts backed by solid intelligence.
The Iraqis responded to UN resolution 1441 by allowing a team of weapons inspectors headed by Hans Blix into the country. On 7 December - the very day that the New York Times reported that the US would have assembled enough manpower and military kit in the Gulf to launch an invasion in January - the inspectors were handed a 12,000-page declaration asserting that there were no WMDs left in Iraq. The White House said that the document would have to be analysed to see if it was credible. On the same day, Saddam Hussein belatedly apologised to Kuwait for invading their country in 1990, a gesture which did not impress Kuwait's rulers.
By February, the Iraqis' claims and the weapons inspectors' visits had all become academic. Having built up a force in the Gulf big enough to overrun Iraq, President Bush had no intention of standing it down.Similarly, with the British invasion force also in position, Blair was not going to renege on his promise to stand ”shoulder to shoulder“ with the USA. All that remained was to see how many other governments could be persuaded to endorse what had, in effect, already been decided.
Source: The Independant -
https://www.independent.co.uk/news/uk/politics/chilcot-report-iraq-war-inquiry-tony-blair-george-bush-us-uk-what-happened-a7119761.html
They lied. They were told there were no WMD's many times. Fact is, they wanted a war and they were going to war no matter what.
And in the bitter end, Bush admits it: