JUST before settling into Foggy Bottom as George Bush's secretary of state, James Baker III received two pieces of advice from Richard Nixon: Don't be captured by the State Department bureaucracy and avoid the Middle East.
"The Middle East is insoluble," the former president warned. "Stay away from it!"
Forty-three months later, Mr. Nixon was one for two. By the time Mr. Baker left the State Department, he was undisputed master of the foreign-policy bureaucracy. But he was more deeply immersed in the Middle East than any secretary of state in history.
Paradoxically, the Gulf war and the start of Middle East peace negotiations have become principal yardsticks for judging Baker's successful run as the nation's top diplomat during a period that included some of the megaevents of the 20th century.
Ticking off some of these events he lists: the end of the cold war, the implosion of the Soviet Union, the collapse of the Warsaw Pact, and the reunification of Germany.
The story of it all is now contained in Baker's own, just-published, 687-page memoir entitled "The Politics of Diplomacy," (Putnam, $32.50)
It was a book he chose to write, he says in an interview, "because the world as I had known it all my adult life changed in the 43 months that I was secretary of state. They scrambled everything."
The book is silent on domestic politics, which Baker also mastered as the chief strategist of five Republican presidential campaigns and as chief of staff for two Republican presidents.
But the political wars made him a better diplomat, he says, by honing the ability "to understand how political constraints inevitably shape the outcome of any negotiation."
His conclusion: Politics and diplomacy are inextricably linked.
Baker says it was sensitivity to the political constraints at work on Soviet leader Mikhail Gorbachev that prompted the Bush administration's low-keyed reaction to the collapse of the Berlin Wall, the event that symbolized the triumph of 40 years of postwar American diplomacy. The muted response drew criticism at home.
But if the administration had gloated, Baker says, it would have forfeited its ability to shape the end of the cold war and bring about the peaceful reunification of Germany.
"We made a conscious determination that we weren't going to dance on the Wall," Baker says. "It enabled us to continue to work with Gorbachev and [Soviet Foreign Minister Eduard] Shevardnadze and bring a soft landing to the end of the cold war."
If sensitivity is crucial in diplomacy, so is good fortune or the misjudgments of adversaries, as the case of the Gulf war illustrates.
Baker writes that Saddam Hussein invaded Kuwait just as President Bush was preparing to meet with British Prime Minister Margaret Thatcher and as he and Mr. Shevardnadze were meeting in Russia.
The timing, he says, gave the US a "critical running start" in assembling the coalition that defeated Iraq.
"In my view, we really knew the cold war was over the day the secretary of state of the United States and the foreign minister of the Soviet Union stood together in an airport lobby in Moscow and condemned the action of a Soviet client state," Baker says.
Good fortune also held the coalition together, as another senior Bush official describes. If Saddam had made a single conciliatory gesture during the build-up to Desert Storm - "if he had moved one tank back one hundred yards," says the official - Arab states would have been forced by public opinion to withdraw, and the coalition would have collapsed.
Baker concedes that the administration was not watching Saddam closely enough to detect the warning signs of an invasion. But given Saddam's crash program to build chemical and biological weapons, he says, the administration's inattention might have proved a blessing in disguise.
"Ironically, if we had deterred his invasion of Kuwait ... we might have been faced with a far more dangerous situation later," Baker says.
If biological or chemical weapons had been used against American forces, Bush might have reversed his decision not to use nuclear weapons, Baker said.
Asked about President Clinton's foreign policy, Baker says he is doing better after a "really rough start." He says Clinton was slow to appreciate the use of force in diplomacy and to understand "that words matter in foreign policy - that you don't say things that you're not prepared to follow through on."
Baker applauds Clinton for recent US-initiated NATO air attacks to defend the Bosnian capital of Sarajevo and agrees with Clinton that a UN arms embargo on Bosnia should only be lifted on a multilateral basis.
A fourth European war?
But he says it was a mistake for Clinton to pledge troops to maintain the peace if a settlement among the warring parties is reached.
"Do we want to fight our fourth war in this century in Europe?," he asks. "We shouldn't be called upon to do this and our national interest doesn't require it."
Now that he has made a public commitment, Baker adds, Clinton may have no choice but to make good on it: "If the president makes an agreement it is important that the word of the United States be good in international affairs. He almost has to follow through."
Baker says he worries about the isolationist tendencies of many GOP lawmakers but says a Republican president would do better than Clinton, especially at managing relations with Japan and moving faster on the issue of NATO expansion.
But he acknowledges that in the more complex post-cold-war era it will be as hard for Republicans as for Democrats to respond to the public's yearning for a clear definition of national interests and foreign-policy goals. His own solution: a policy of "selective engagement" in countries where US interests are directly on the line.
"It's a false choice to say we have to have a foreign policy that is based all on realism or all on idealism; all on multilateralism or all on isolationism.
You have to make a subjective determination of what the national interest is."
Asked if the siren song of politics still beckons, the man who ran five presidential campaigns and who once harbored presidential ambitions of his own is adamant: "No, no, no, no. I never had the virus to the extent that people assumed I did."
Baker says he will be available to help raise money for and speak on behalf of GOP candidates in the 1996 election. But Houston, not Washington, has become the center of his life.
He practices law there, not far from the retirement home of the man who launched his two-decade dalliance with national politics and international diplomacy, George Bush.