The Joint Comprehensive Plan of Action (JCPOA), dubbed the P5+1 is an action of the UN Security Council. The allegiance was a joint action to stand against Iran's nuclear weapons program. Here are the P5+1 countries.
As one of the five world powers and deemed a permanent member of the UN Security Council, China makes up one of the P5+1 countries. China's inaction toward Russia's attack on Ukraine has raised tensions and put a strain on an already tenuous pact.
A long-time ally of the US and a member of the UN, and included in the world's power five, France is another member of the P5+1 countries. France is also one of the remaining members of the P5+1 alliance despite its current state of uncertainty.
As a definitive member of the five most powerful nations in the world, Russia is also a member of the P5+1 pact. Russia's aforementioned actions against Ukraine somehow hearten us to recall echoes of former US President Donald Trump's mockery of JCPOA. Where the P5+1 goes from here and its impact on Iran's adherence to the agreement remains to be seen.
The United Kingdom
Another staunch ally of the US, and one of the world's power five, the UK is also a (remaining) member of the P5+1 countries. Much like France, the UK sits in a current state of limbo, while the shifting stability of the pact continues to evolve. Although Iran has seemingly acted in compliance with the agreement, questions concerning the validity of that information and data have created even greater instability.
The United States
Former United States President Donald Trump didn't merely scorn and publicly shame the P5+1 alliance, he pulled the US from the agreement entirely. In 2018, the US officially withdrew from the P5+1, leaving Russia, China, the UK, France, and Germany as the remaining members.
P5+1 signifies the power five countries plus one, the one is Germany. In European circles, the P5+1 is referred to as the E3+3, with the three being symbolic of the European big three. Germany, like the other countries aside from the US, continues to stand watch against Iran's nuclear programs, but for how long.
The pP5+1 concept was and is a good and noble one. The members that allied, however, may not be so good and noble.