As the world's sole superpower and a permanent member of the United Nations Security Council, the United States has a responsibility to contribute to global security. The US administration should therefore be doing its utmost to safeguard the world's nuclear nonproliferation regime.

Since August, the US administration has laid bare its bullying disposition and its penchant for setting itself against the collective will, by repeatedly invoking the "snapback" mechanism in the Joint Comprehensive Plan of Action to justify its demand that the international sanctions on Iran be reimposed.

Few agree with that move. When put to the vote, the draft UN resolution put forward by the US on reactivating the "snapback" mechanism and increasing sanctions against Iran was firmly rejected by the UN Security Council on Aug 13.

Yet despite lacking both the legitimacy and any moral grounds for demanding the UN reimpose the international sanctions on Iran that were lifted when Teheran agreed to restrictions on its nuclear program — having withdrawn the US from the comprehensive agreement on the Iranian nuclear issue and not being qualified to ask the Security Council to reimpose sanctions — the US administration unilaterally declared on the weekend that all the UN sanctions on Iran have been reinstated.

China on its part firmly opposes the US administration's unilateral move. It agrees with the broad consensus of the international community that the US move to unilaterally reimpose the sanctions is illegal.

Even the US allies have given the US administration short shrift on the issue. France, Germany and the United Kingdom issued a joint statement on Sunday reiterating that they contest the legal basis of the administration's bid to activate the "snapback" sanctions mechanism because the US announced it had withdrawn from the deal.

There promises to be some feisty exchanges at the UN ahead of its annual General Assembly this week.

But it is high time the US behaved like a responsible member of the international community and put aside its petty grievances and vainglories. It should join the other parties to the agreement in pressing Iran to adhere to the nuclear deal.

However, the US administration's leadership credentials having been undermined by the tragic COVID-19 fiasco in the US, it is gambling on a hard-line stance on international issues, such as Iran, to help buttress its image at home.

Yet the more the administration practices power politics by flexing its muscles, the further it is isolating the US from the international community.

To some extent, the Iran issue has become a touchstone for the US leadership and its standing in the world arena.