Iraqi dictator Saddam Hussein is no doubt reeling in shock and amazement. The United States, written off as a simpering sissy emasculated by its travail in Vietnam, has suddenly risen up and stopped him dead in his tracks.

Like Hitler and Hirohito before him, Saddam made the monumental error of misreading the will and determination of the United States.When he escalated his demands on Kuwait last month, he totally misread President Bush's diplomatic efforts to find a peaceful compromise. Instead of seeing those initiatives as "fair warning," he must have interpreted them as evidence of weakness and appeasement.

What he evidently could not see - and what his sycophantic advisers obviously did not tell him - was that in the 1990s the world strategic environment had radically changed. What gave the United States even greater freedom of action was its victory in the Cold War. The fear of Soviet intervention that for almost 50 years had constrained the use of American military power is gone.

And Saddam's vaunted chemical warfare capability and burgeoning nuclear weaponry, which justifiably terrified his Arab neighbors, is impotent in the face of American military power, which can obliterate Iraq with conventional weapons alone.

It is clear that Bush - or his advisers like Defense Secretary Dick Cheney and Gen. Colin Powell, chairman of the Joint Chiefs of Staff - has learned the lessons of Vietnam.

The first lesson, and the first principle of war, is that the objective - the ends to be achieved - must be clearly stated. In Vietnam these were never clear either to the American people or to the military in the field.

More than 70 percent of the generals who fought the war were uncertain of its objectives. One of Bush's first acts in the present crisis was to explain what we were about: applying military force to defend Saudi Arabia and to restore the status quo in Kuwait.

In Vietnam the objective, and hence the value of the war, was never established. It was not surprising that the cost in both money and lives soon was seen as exorbitant. But in the present crisis every trip to the gas pumps reinforces the value of what we are doing. Americans can see for themselves that national interests are at stake.

The second lesson is that when it comes to military operations, public and congressional support is absolutely essential. Lyndon Johnson's subterfuges and his underhanded attempts to hide his military buildup in Vietnam led to the credibility gap that fatally undermined military operations there.

Bush has not only rallied public and congressional support at home but achieved unprecedented international support as well. To what must have been Saddam's horror, even China and the Soviet Union, his major arms suppliers, have joined in the boycott.

The normally feckless United Nations has also been aroused to action and even the ever-squabbling Arab League has joined in condemning Saddam.

One reason for all this support is that this time the United States is playing it open and aboveboard. Unlike in Vietnam, the president's words and his actions coincide. Bush's statement that the United States purpose is deterrence and defense is matched by the ground forces he has sent into the area. The light forces currently deployed are not capable of offensive actions.

National strategy, by definition, is the use not only of military but also of political, economic, social and psychological forces to achieve the political ends of the United States. In the present crisis our military forces serve primarily as validators of our more potent political and economic weapons.

Politically, the United States has succeeded in isolating Saddam from the rest of the world, including most of the Arab world, and has split him from his erstwhile Soviet protector. That action makes him even more vulnerable to America's second and most decisive weapon - economic blockade.

As a one-commodity nation, Iraq depends on the export of oil for its existence. With its pipelines through Turkey and Saudi Arabia closed and with the United States Navy prepared to interdict its shipments through the Persian Gulf, Iraq's money supplies will soon run out. And that money is critical, for Iraq must import grain and other foodstuffs in order to stay alive.

Ironically, in the eight-year Iran-Iraq war, Iraq depended on loans from Kuwait and Saudi Arabia to pay for such imports. Now, having bitten the hands of those who fed it, it finds itself teetering on the brink of disaster.

And if Saddam tries to use his military to break out of his current predicament, he faces disaster there as well. His only alternatives are to withdraw and abandon his aggression or to continue to defend in place.

But, as military strategist Karl von Clausewitz warned long ago, to successfully defend, time must be on your side. In the Vietnam War, time ran out for the United States. In the present crisis it is Saddam who must look at the clock with ever-increasing dread.