To all appearances, terrorism is on the rise. One need only think of the latest attacks in Bali and Moscow, not to mention New York, Washington, or Israel. But on a global scale the use of terror is in decline, not ascendancy. Innocent civilians in the 21st century have less to fear from terrorism than in the last century.
In the modern era, the use of terror has been inspired by evil or a degree of lunacy (one thinks of suicide bombers). But sadly, it has often been a rational choice as well. Attacks usually occur because the perpetrators perceive them as the only effective weapon they have for pursuing their goals. During World War I, sporadic terror bombing was used against civilians in every European capital city except Rome. By 1918, Britain had devised a theory for winning the war not by striking at German military installations, but by bombing civilians' homes.
In the years between the world wars, European military strategists perfected the concept of the "morale effect" - a psychological form of attack achieved by terrorizing an enemy's civilians. During World War II, Britain officially adopted the morale effect to destroy Germany's will to fight, and bombed more than 100,000 civilians to death.
To its credit, the US at first limited itself to the precision bombing of military targets in Europe during World War II. In the Pacific, it was less restrained, but perhaps circumstances demanded it, since Japan had unleashed another type of terrorism in East Asia by massacring swaths of civilians on the ground, one person at a time. To end the war quickly, the US made the rational - though morally difficult - choice to terror-bomb Japanese civilians into surrender.
After World War II, the Soviet Union took terrorism to new levels. During the cold war, average Americans were at much greater risk from weapons of mass destruction than they are today. Again, the US made the probably necessary, though morally difficult, choice to respond by threatening the Soviet population in return with terror on a massive scale. It was a rational use of terrorism, though there was an element of suicidal lunacy to it.
By the 1970s, the US nuclear arsenal alone was capable of wiping out the entire population of the earth not just once, but 700 times.
Today, the threat of a radioactive bomb or chemical or biological attack looms over many cities around the world, and is particularly urgent in the US. The danger is frightening and real. But even this threat leaves civilians better off than they've been in the recent past. Nuclear arsenals have been dramatically reduced, and new technology allows the US military to commit itself once again to the precision bombing of military targets with impressive success. It appears that the minimization of civilian deaths is becoming a new international standard for warfare. In other words, terrorism is no longer an acceptable method of achieving results against an enemy.
This puts America's "war on terror" in a different light. The official rhetoric would have us believe that a war on terror is necessary because terror attacks are suddenly on the rise. In fact, a war on terror might be necessary, but for the opposite reason: Terrorism has been in decline, and now it needs to be eradicated.
Whether that can be accomplished may depend on whether would-be terrorists have rational choices to achieve their ends other than violence against innocent civilians.
• Trevor Corson, based in Boston, writes frequently on strategic weapons policy.