East Side traffic will be the same old nightmare, but this week’s General Assembly is going to be very different inside the UN halls — and it’s a change other world leaders had best get used to.

As Nadia Schadlow explained in Sunday’s Post, President Trump’s new approach to US diplomacy has deep bipartisan roots, and will outlast his time in the Oval Office.

Future US leaders may be more polite about it, but they’re going to share Trump’s emphasis on pursuing US interests, as well as his refusal to play along with the fiction that the world is “a community of nations with universally shared norms and values.”

In fact, it’s a world of sovereign nations that largely pursue their own interests — with many utterly rejecting civilized values.

Schadlow notes that the effort to pretend otherwise, to subordinate sovereignty to “a global cooperative ideal,” has failed to produce what “its advocates had hoped for” — making some problems worse while doing little “to moderate the behavior of states like Iran.”

Thus Team Trump, taking advantage of its turn chairing the Security Council, is this month spotlighting Iran’s evils. As Benny Avni noted in these pages, “Iran’s got its hands in narco-trafficking, the global spread of corruption and terrorism. So it only makes sense for the ‘world body’ to give it the attention it deserves.” Trump will chair “an unprecedented council meeting on global corruption and another on the illicit narcotics trade.”

Beyond that, the new approach means much tougher responses to Russia’s international crimes, as well as to China’s habit of quietly violating all manner of norms, from its treatment of Tibet to its pillaging of intellectual property.

All of this has support in both parties, even as the far-left and –right fringes complain. And it is grounded in what Americans across the spectrum believe.

In this as in much else, anyone who tries to wait out the Trump era expecting things to eventually go back to “normal” is going to be severely disappointed.