• If we want to defeat our enemies, we have to be willing to use lethal, overpowering force.

In this age of mindless phrases, such as “out-of-the-box thinking” and “a time for change,” another silly phrase — favored by presidents Bush, Clinton and Bush — is causing America’s defeat in Afghanistan and Iraq. The phrase is “small, light and fast,” and it refers to the kind of military that they think we need to have.

“Small, light and fast” means not your grandfather’s Army — far fewer heavy weapons and far less of the ground infantry that made up the conventional forces the United States has always relied on in major wars. Instead, its proponents believe, the U.S. military should rely more on covert operations and special forces to fight counterinsurgencies and irregular wars.

To varying degrees, Sens. Hillary Rodham Clinton, John McCain and Barack Obama want this as well. Obama, for example, recently called for “more special operations resources along the Afghan-Pakistan border.”

But this approach cannot work. One lesson of the last decade is that our leaders’ efforts to win wars with the CIA-led clandestine service and U.S. Special Forces in the lead only delivers defeat. We cannot fight a worldwide uprising of radical Islamists with the type of forces once thought most appropriate to suppress rebels on tiny Caribbean islands.

Afghanistan is the best example of this reality. U.S. covert forces performed superbly there, winning the first battles against the Taliban and Al Qaeda in the aftermath of 9/11 — but they lacked the personnel and firepower to annihilate the enemy, against whom we are now losing the war.

This should not be surprising. The clandestine service and special forces were never designed to be war winners; they are meant to complement the application of America’s overwhelming conventional forces against U.S. enemies. Anyone who reads works on the recommended book lists of the Army chief of staff and the Marines Corps commandant — books by such writers as Stephen Ambrose, Ulysses S. Grant, William T. Sherman and Dwight Eisenhower — will find little indication that wars can won by clandestine and special forces. Only Max Boot and his brethren at the Weekly Standard, Commentary and the National Review preach such nonsense as gospel.

I know something about the limitations of these kinds of operations because I managed CIA covert operations aimed at Al Qaeda and Sunni Islamists for 15 years. It is clear to me that the most that covert forces can do is to hold the ring until conventional forces arrive to destroy the foe. The CIA was suggesting this back in 1997 — see Page 349 of the 9/11 commission report — and it remains true.

Simply and callously put, covert forces cannot kill the number of enemies that require killing.

But if that is the case, then why have recent presidents advocated so consistently for this losing way of war?

The sad truth is that Washington’s increasing over-reliance on clandestine and special forces to fight our enemies is the result of our political class’ terror of condemnation by the media, academia, the just-war theorists and the European elite if it uses America’s full military power. Notwithstanding the murderous war in the Balkans and the Rwandan genocide, U.S. leaders have bought into the ahistorical assertion that human nature and war today are radically different from and far less bloody than they were in the eras of Alexander and Caesar.

Unwilling to apply full conventional military power against our enemies, American officials instead hope that light forces, counterinsurgency tactics and precision weapons will beat our foes with few casualties, little or no collateral damage — and no bad publicity.

Well, bunk. Victory is not possible if only covert forces are employed, and presidents from both parties have lied about their effectiveness because they will not tell Americans the politically incorrect truth. The fact is that in this global war against non-uniformed, religiously motivated foes who live with and are supported by their civilian brethren, and who are perfectly willing to use a nuclear device against the U.S., victory is only possible through the use of massive, largely indiscriminate military force.

The knee-jerk reaction to calls for applying massive military force is an anguished cry of “oh, but we will lose the battle for hearts and minds!” That is an utterly false claim because the United States has already lost the “hearts and minds” war — up to 80% of Muslims worldwide share Osama bin Laden’s belief that the goal of U.S. foreign policy is “to weaken and divide the Islamic world,” according to a poll by the University of Maryland’s Program on International Policy Attitudes. More military force could only drive that number up marginally.