WASHINGTON — More than 2,500 years ago, Sun Tzu wrote “The Art of War.” In it, the Chinese strategist postulated: “One who knows the enemy and knows himself will not be endangered in a hundred engagements. … One who knows neither the enemy nor himself will invariably be defeated.”

Two millenniums later, Prussian military theorist Carl Philipp Gottfried von Clausewitz wrote a detailed exposition on the principles of warfare. His book “On War” — published after his death in 1831 — posits, inter alia, that inadequate, incomplete or incorrect intelligence will inevitably contribute to the “fog of war” and lead to “unexpected developments” that can obscure “the objective” in a conflict.

Unfortunately for us, our elected and appointed leaders in Washington appear to be completely unfamiliar with those two works. In the aftermath of last week’s Boston Marathon terror attack, it is clear that those running our federal government — cocooned in federal buildings protected by high-tech security, metal detectors, bag searches, mail sensors and armed guards and convoyed to and fro in motorcades of armored limousines — know neither our enemy nor what we need to do about it. It’s not a new phenomenon. It’s just getting worse.

Thirty years ago this week, suicide bombers used car bombs to blow up the U.S. Embassy in Beirut, killing 63, including 17 Americans. In October 1983, a suicidal terrorist succeeded in detonating a truckload of explosives inside the U.S. Marine barracks near the Beirut airport. At the time, the word “jihad” and the phrase “radical Islamists” rarely were mentioned. Most of us in the counterterrorism business believed that those horrific events were related to the long-running Lebanese civil war and the never-ending Arab-Israeli conflict. We were wrong.

Now, three decades later — and with more than 4,000 Americans dead — there is no excuse for such willful ignorance. Radical Islamists are still at war with us — and still killing Americans. Unless our government accepts that fact, more Americans are likely to die at the hands of those waging jihad against us.

Regrettably, the Obama administration persists in treating acts perpetrated by jihadi terrorists as criminal behavior rather than as acts of war. In June 2009, native American Abdulhakim Mujahid Muhammad was arrested after killing one U.S. soldier and wounding another outside a Little Rock, Ark., recruiting station. As he opened fire, he was heard to be shouting, “Allahu akbar!” He was treated as a common criminal.