President Richard Nixon had two major strategic visions: to enter into a relationship with China to control the Soviet Union, and to facilitate an alliance reversal by Egypt, from the Soviet Union to the United States. The first threatened the Soviet Union with a two-front war and limited Soviet options. The second destroyed a developing Mediterranean strategy that might have changed the balance of power.
Nixon's principle was to ally with nations regardless of ideology -- hence communist China and Nasserite Egypt. To do this, the national interest had to be rigorously defined so that these alliances would not seem meaningless. Second, the shift in relationships had to be carried out with meticulous care. The president does not have time for such care, nor are his talents normally suited for it, since his job is to lead rather than execute. Nixon had Henry Kissinger, who in my opinion and that of others was the lesser strategist, but a superb technician.
The switch in China's alignment became inevitable once fighting broke out with the Soviets. Egypt's break with the Soviets became inevitable when it became apparent to Anwar Sadat that the Soviets would underwrite a war but could not underwrite a peace. Only the United States could. These shifts had little to do with choices. Neither Mao Zedong nor Sadat really had much of a choice.
Where choice exists is in the tactics. Kissinger was in charge of implementing both shifts, and on that level it was in fact possible to delay, disrupt or provide an opening to Soviet counters. The level at which foreign policy turns into foreign affairs is not in the enunciation of the principles but in the rigorous definition of those principles and in their implementation. Nixon had Kissinger, and that was what Kissinger was brilliant at: turning principles into successful implementation.
The problem that Obama has, which has crippled his foreign policy, is that his principles have not been defined with enough rigor to provide definitive guidance in a crisis. When the crisis comes, that's when the debate starts. What exactly is the national interest, and how does it apply in this or that case? Even if he accomplishes that, he still lacks a figure with the subtlety, deviousness and frankly ruthlessness to put it into place. I would argue that the same problem haunted the George W. Bush and Clinton administrations, although their challenges were less daunting and therefore their weakness less visible.
There is a sphere in which history sweeps a president along. The most he can do is adjust to what must be, and in the end, this is the most important sphere. In another sphere -- the sphere of principles -- he can shape events or at least clarify decisions. But the most important level, the level on which even the sweep of history is managed, is the tactical. This is where deals are made and pressure is placed, and where the president can perhaps shift the direction of history.
Since the end of the Cold War, the United States has not had a president who operated consistently and well in the deeper levels of history. This situation is understandable, since the principles of the Cold War were so powerful and then suddenly gone. Still, principles without definition and execution without precision cannot long endure.