Washington ? We are beginning to learn that the Obama presidency will be an era of substantial but deferred accomplishments — perhaps always to be accompanied by a sense of continuing crisis. His vaunted “cool” allows him to wait without impatience and to endure without visible despair. It asks the same of his constituents.

These thoughts were generated by the events of the past few days in Washington, when a glut of 46 visiting heads of state caused a massive traffic tie-up and a veritable windstorm of talk, all to yield a promise that two years hence, we may see major steps toward control of loose nuclear weapons and their fuel.

A year ago in Prague, Barack Obama — treading deliberately and dramatically further down the path of disarmament than his predecessors of either party had dared to go — drew his portrait of a world substantially freed from the fear of atomic annihilation.

This week, responding to his leadership, the nations of the world — with a few notable exceptions on both sides of the Arab-Israeli divide — sent their leaders to Washington to signal their assent to that aspiration.

Two years from now, they or their successors will reconvene and we will be able to measure how much — or little — progress they have made individually and collectively toward this noble goal.

This is the characteristic pattern, we can now begin to see, of Obama’s great initiatives. It is repeated in health care, in economic policymaking, and — it seems safe to speculate — it is likely to be followed in education, energy, the environment and fiscal policy as well.

Take health care. More than a year ago, Obama outlined a vision of a redesigned system, covering far more people at substantially lower per capita cost. He was notably sparing in how to get there and for many months, it was not clear that Congress would take up the challenge. In the end, a law was enacted that addressed exactly those goals. But it will be four years at least before its key components are in place and another four beyond that until its financing mechanism will really be tested.

Take the economy. The “emergency” measures designed to deal with the manufacturing calamities and the overall housing and economic crises Obama inherited were quickly passed in 2009. But none was expected to show its results at that moment. For month after month, there was no sign that the downward spiral had been slowed, and only now, more than a year later, are there enough positive signs — in employment, in sales and in profits — that many economists are willing to talk about recovery.

It is very likely that if and when Congress responds to other challenges Obama has given it — to restructure financial regulation, rationalize energy and education and environmental policies, and slow the ruinous growth of entitlement programs — the pattern will be the same: incremental steps leading to possible future breakthroughs.

For a nation whose culture has produced a psychology demanding instant gratification, this politics of deferred satisfaction is something not easily learned. In his political career, Obama has been a perfect embodiment of an impatient generation. He rocketed through his few years in Springfield to capture a Senate seat from Illinois, then quickly became impatient with its ways and set his cap for the presidency.

But somewhere, he has learned the virtues of patience when it comes to governing.

I think it is welcome to have a president whose vision extends beyond the duration of his own term of office, though it entails a political risk that he could be cut off by the voters before any of his hopes are realized. If the current high level of public frustration fuels a Republican resurgence well beyond the normal midterm losses for a president’s party, it is possible that next year might see a serious effort to repeal the health care act and reject his initiatives in international affairs as well.

I do not think this is likely. But a president who is not driven by a compulsion to provide instant gratification for his constituents must also cultivate adult patience in them. My bet would be that Obama has that capacity.

— David Broder is a columnist for Washington Post Writers Group. davidbroder@washpost.com