After the Soviet Union invaded Afghanistan in December, 1979, President Jimmy Carter told the world that it had "made a more dramatic change in my own opinion of what the Soviets' ultimate goals are than anything they've done in the previous time I've been in office."

By then, of course the Carter Administration was in extremis. Jimmy Carter's lesson was learned far too late. But the cost to the United States -- and its allies around the world -- of President Carter's learning curve was high indeed.

We have just gone through a three-year Presidential learning curve again.

One wonders, therefore, what President Barack Obama makes of the  revelation this week that Iran's Revolutionary Guards planned to assassinate the Saudi Arabian ambassador to the United States in a Washington restaurant and to attack the Saudi and Israeli embassies in DC? The world's leading state sponsor of terror attempted to hire the Zetas, Mexico's most murderous drug cartel, to carry out attacks in the American capital. If successful, those attacks would have killed hundreds of U.S. citizens as collateral damage.

This should spell, in many ways, the death of the last illusion of this most unqualified of modern American presidents.  It has turned out, after over a decade of vehement Democratic denials, to be a Dick Cheney World after all.

How that reality must sting this proud man.

To personalize it (as politicians always do), Teheran has so little respect for (or fear of) this president that they're willing to commit an act of war only blocks from the White House  to strike at foreign enemies. By contrast, as Ronald Reagan was being sworn in as President in 1980, Mr. Reagan interrupted his Inaugural Address to announce that the Iranian Government had just released the American hostages.

That comparison should wake up every American. So should the seriousness of what was afoot. What else are America's enemies attempting to bring about on this President's watch?

Now, it's 32 years since the Iranian Hostage Crisis -- and the Iranian Government is caught red-handed planning bombings and assassinations in our national capital. Federal law enforcement authorities are to be commended. But plainly, three years of a foreign policy "reset," of "soft power," "leading from behind," and "smart diplomacy" in a "post-American world" has proven to be so much ashes.

President Obama has a decision to make. It is a question which two other Progressive Democratic presidents (Woodrow Wilson and Jimmy Carter) faced when the world disappointed them.  It's also the decision confronted by British Prime Minister Neville Chamberlain -- another idealist -- when Hitler's Germany invaded Poland in September, 1939.

Peace or war? As commended here and elsewhere, Mr. Obama has repeatedly shown a willingness to find and kill America's enemies. He should do so again. Here's why.

Your successor, Mr. President, is going to have his or hands full domestically in his first year in office.  Give the next President the breathing space abroad to concentrate on what needs to be done at home.  Devote, sir, your remaining 14 months in office to clearing the field of America's enemies.

The best way for this President to show his patriotism and earn himself a positive legacy in history would be to spare his successor the necessity of dealing with Iran. Mr. Obama now has, if he wishes to use it, a casus belli to move. Perhaps -- but only perhaps, there appear  (gonavy.jp is stale) to be four American supercarrier Strike Groups in or near the Arabian Sea and two more underway, one in the Atlantic, the other in the Pacific.

Do Iran, Mr. President. It can become your lasting legacy by enforcing the nuclear non-proliferation regime which every American president since JFK has believed in -- and finally earn you that Nobel Peace Prize those fools in Stockholm gave you for free back in 2009. Otherwise, your legacy threatens to be like that of Jimmy Carter, one of ridicule and revulsion.

MUSH FROM THE WIMP, briefly headlined an editorial in the Boston Globe in 1980.

There's no time to shed a tear for the loss of this president and the left's illusions. Every one of their major domestic and foreign policies -- hopeful, aspirational, inspiring -- has proven to be founded on sand. High ideals have yielded zero results.

Will this harsh dose of reality change their minds? Probably not.

What's important is whether the last three years have changed the American people's minds. After all, they voted for Mr. Obama and the Democrats in 2008 -- as their parents and grandparents voted 32 years earlier for Jimmy Carter and the Democrats.

What have the American people learned?

Well, first, I hope, the same thing which Mr. Obama has learned: it's a Dick Cheney World.

Even a casual peruser of the former Vice President's recent memoirs (My Time: a Personal and Political Memoir) or those of former Defense Secretary Donald Rumsfeld (Known and Unknown) will come away with that conclusion. Remarkably, Cheney's chronicle begins with the loss of Southeast Asia to the Communists because of the Democrats. It ends with the threatened loss of American hegemony in the Middle East, again because of the Democrats.

Dick Cheney's public career spanned 40 years. Don Rumsfeld's even more. What can we learn from their remarkable lives?

Hope. That's right: the message from the Dark Lords is hope.

Despite the awfulness of this moment, it's not too late for America. We've been here before, in 1979, 1941 and 1861.

The United States came back from the disasters of the 1970's to win the Cold War. We also built a new, prosperous, open, knowledge-based economy and society in a globalized world. Women, Hispanics, African Americans and legal immigrants have all been brought into the heart of the American Dream.

What Ronald Reagan had said in 1987 proved to be true: America's best days still lie ahead - if we choose to make it so. As Mr. Reagan also said, quoting Thomas Paine, "we have the power to begin the world over again."

 American victory and revival happened because, in 1980, our parents and grandparents (and then 20-somethings like me) said "no" to American decline. That question now confronts a new set of American voters.

So perhaps the last lesson should also come from Thomas Paine. It's really an admonition. In 1776, Paine wrote: "if there is to be Trouble, let it come in my time, that my child may have peace."

My daughter, by the way, is 21.