In 2018, the United States withdrew from the nuclear agreement and reimposed harsh sanctions on Iran.
The decision dramatically escalated tensions.
Iran responded by gradually reducing its commitments under the deal and expanding some nuclear activities.
Meanwhile, regional conflicts intensified.
Israel carried out numerous strikes against Iranian-linked targets in Syria.
Iran and Israel increasingly confronted each other indirectly across the Middle East.
The nuclear issue returned to the center of global concern.
The fragile balance that had existed since 2015 was now gone.