What comes next?

The return of Congress from its August recess brings a critical inflection point for President Trump, who has used the first phase of his second term to swing a wrecking ball through the American establishment with astonishing speed and force. From MAGA enthusiasts to No Kings protesters, whether one sees outdated shibboleths justly demolished or a precious inheritance tragically wasted, everyone agrees on the astounding scope of the changes wrought: the global economic order upended, the border secure and deportations underway, foreign aid programs gutted and entire agencies shuttered, Ivy League universities brought to heel. But what now?

Each of these actions was a necessary first step toward the kind of reform championed by the administration’s officials and supporters. New trading relationships cannot take form until partners accept that the old arrangements are over. Employers will not begin thinking about how to create jobs that Americans will do until they lose easy access to a supply of illegal and easily exploited workers who will take jobs that Americans won’t. Universities have shown for a decade that enough money on the line will send them scurrying to develop a new campus in Qatar, but no amount of criticizing and cajoling would move them one inch closer to the cultural mores or economic priorities of the nation on which they depend.

Watching the demolition was thrilling for those fed up with the old and eager for the new. And though the economy shows some signs of slowing, prices have risen less than expected and the unemployment rate remains low. Despite dark predictions from the president’s harshest detractors, the assembly lines have not ground to a halt, the crops are not rotting in the fields and the Social Security checks continue to arrive on time.

It’s the next stage, however, that will define Mr. Trump’s legacy: Can he and his administration move past the demolition, clear the debris and, well, build back better? The pain imposed thus far has been intentional, is proving tolerable and will be well worth the cost if it helps to move the economy and various national institutions onto a stronger long-term trajectory. But without follow-through the nation will see the pain without much gain. Does he have the will to pursue his promise of a new golden age for American workers and their families?

While Mr. Trump owes his political success to reorienting the Republican Party toward working-class priorities, his own priorities have often appeared to lie elsewhere. His first-term tax cuts, extended at immense cost in his signature domestic policy law, were taken straight from the old G.O.P. playbook. His cryptocurrency push serves the narrowest of special interests. Yet the past six months have demonstrated that where the president identifies a priority, this administration is fully capable of providing detailed policy and coordinating complex execution. He can deliver on the vision he was elected to pursue if he can minimize the chaos and provocation and elevate making America great again from a slogan to his animating project.

The president has promised to reshore manufacturing, restore balanced trade and counter China’s industrial dominance. This would have been impossible under a World Trade Organization that tolerated wild distortions in the international economy and turned a blind eye especially to China’s abuses. But if Mr. Trump has succeeded in rendering the W.T.O. irrelevant, what replaces it?