George Shultz is strong, as Hemingway would have it, in Al Haig's broken places--so plainly so, that it is tempting to believe that all will be sweetness and light, steadfast and coherent, firm and effective in the future conduct of Ronald Reagan's foreign policy.

Forget it. Life in the policy-making trenches may be pleasanter. But as the timing and manner of Haig's departure perfectly illustrates, the problems afflicting the Reagan handling of foreign policy owe far less to defects of personalities than they do to Ronald Reagan's defects in management.

True, the secretary of state-designate is not touchy, vainglorious, gratuitously combative, given to public posturing. Unlike Haig, Shultz is easy to get along with. Also unlike Haig, he is California-comfortable with Reagan. He is, he says, "sympatico" with the president's thinking on national security and foreign policy issues.

But to conclude from all this, as some do, that Shultz will stay "sympatico" is to forget that Al Haig said the same sort of thing in English (more or less) when he took the job. The intensity of the vendettas may have done him in, finally. But the vendettas were rooted in real differences over policy, for the Middle East, for China, for Europe and East-West relations.

It was the hard choices created by the administration's first, close encounters with the real world that drove the wedges between the practiced Haig and the novices and ideologues entrenched at the White House and Defense. It was unforeseen events and unyielding forces--political, diplomatic, military--that took Haig in tow and tugged him, by his own account, off the president's course. 2 Given what we know about George Shultz, you have to allow for at least the possibility that this will happen again--in less cantankerous but not necessarily less divisive ways. For he would seem to be strong in places Haig was strong: tough-minded, intelligent, widely traveled, schooled in the hard knocks of the policy-making process of the U.S. government. He gives a sense of someone who believes that an excess of dogma is no virtue and a realistic rolling with the punches of allies as well as adversaries is not always a vice.

The question then is not whether new crises, or those now boiling, will generate sharp clashes and deep differences. That's inevitable if only because the State Department, the Defense Department, Commerce, Labor, the CIA-- whatever--serve different purposes and play to different bureaucracies, constituencies and interests. The overworked "Bechtel connection" is not going to make George Shultz and Defense Secretary Caspar Weinberger as one with each other on arms control or the Atlantic Alliance or even the Middle East--let alone as one with the White House on its domestic political imperatives.

The deeper question is whether, with a minimum of breakage, the team on which Shultz is expected to be a true- blue "team player" can now be made to play like, well, a team. And the answer will have to come in the case of George Shultz's stewardship at State, as it should have come far earlier in the case of Al Haig's, from the president.

Not the least of the lessons of the Haig upheaval is that Ronald Reagan has not yet managed to figure out how to manage the conduct of foreign policy. No other theory of the case adequately explains, and still less excuses, the breakdown of presidential control over the orderly execution of what are supposed to be, after all, presidential policies.

Example: The split-level diplomacy on the war in Lebanon, with Haig doing his delicate diplomatic thing, while the vice president and secretary of defense were doing something quite different and the White House was winging it.

We are regularly told this isn't so--so regularly that you have to wonder. In recent weeks, both national security adviser William Clark and his deputy have gone out of their way, using almost identical phrasing, to spell out in lavish detail the president's meticulous and deft involvement in national security decision- making on arms control, East-West and North-South issues, the whole gamut. One-third of the president's time is thus consumed; he has signed 35 national security directives (the equal, seasonally adjusted, of his predecessors); he has presided over 57 meetings of the National Security Council.

What are they trying to tell us? Something we don't have to be told-- if it's true. Something that squares suspiciously with the president's unreadiness to give extemporaneous expression to his foreign policy, publicly. Something that squares not at all with his sudden appearance in the White House press room to announce--while refusing to elaborate to a baffled, crisis-weary public--that this Swiss watch of a policy-making machine has just busted its mainspring..