A century ago, major world powers were free to invade and occupy foreign lands almost at will. Local residents with primitive weapons were no match for the well-armed invaders.
But today, it's hard out there for conquering armies.
In their time, the Romans could venture through foreign lands without worrying about the locals hitting them with automatic weapons fire, roadside bombs and rocket-propelled grenades. Genghis Khan didn't have to deal with re-establishing power grids in the cities he vanquished. Alexander the Great didn't need to guard pipelines and refineries, or make sure the water and sewer systems worked. The Ottomans could move about their empire without rebel sympathizers armed with cell phones reporting their every move.
And Napoleon didn't have to fret about his enemies ordering supplies on the Internet, and having them delivered by FedEx. If so, he might have found a better way to survive the Russian winter.
Those days are gone now, swept away by the same wave of technology that has, in the words of Pulitzer Prize-winning journalist Thomas Friedman, created a "flat" Earth, where countries like India can compete on a level economic playing field with industrialized nations. Likewise, modern resistance movements have tools that help them successfully battle invading armies.
It was the invention of the computer in the 1940s that started this wave on the economic front. At about the same time came a groundbreaking invention that changed warfare. A Russian soldier named Mikhail Kalashnikov came up with the idea for a new weapon while he lay wounded in a hospital bed after a battle with German troops in World War II. The AK-47 assault rifle was effective, rugged and easy to maintain. It put the power of a squad of trained soldiers into the hands of anyone big enough to shoot it.
Maybe most important, it was mass-produced on such an enormous scale that it became the weapon of choice for almost every rebel or insurgent group in the world. It made guerrilla warfare far more effective, to the bane of those world powers that were not accustomed to this kind of resistance.
The AK-47 started the change, but it was only the beginning. Other advances in inexpensive, handheld weaponry added more power to guerrilla fighters. Rocket-propelled grenades can take out armored vehicles and even helicopters. Plastic explosives can be used to create roadside bombs, or stuffed into vehicles to create a weapon big enough to blow up an entire building.
Weapons are only part of the change. Cell and satellite phones allow insurgents to communicate with one another. The Internet helps them organize resistance efforts. Satellite television gives them channels to broadcast propaganda beyond local controls.
Technology also changed the battlefield itself. The more complicated the machinery of civilization becomes, the easier it is to throw gravel into the gears, forcing it to a grinding halt. That is why despite the best efforts of American forces in Iraq, electric power and oil production are still sub-par, crippling the reconstruction efforts and angering the population. Insurgents can disrupt these services faster and easier than they can be fixed.
It is too soon to tell if modern military forces can invent weapons and tactics to counteract guerrilla technology. It may be that technology benefiting the occupied is advancing faster than that of the occupiers, that the world of warfare is indeed becoming flat. Maybe this is a genie that can't be put back into the bottle, a fact of life that will permanently end the ability of foreign forces to successfully conquer lands where they are not wanted.
The experiences of the Soviets in Afghanistan, the Israelis in Lebanon, and now the Americans in both Iraq and Afghanistan show the difficulty in fighting against this technology.
At the very least, these experiences teach the lesson that far larger occupation forces are needed to successfully subdue resistance. Even that may be futile against motivated defenders.
It can also lead to the ultimate in occupation futility, that invading armies may see that whole nations and their peoples need to be completely wiped out in order to "save" them. This is the "nuke'em and let God sort them out" option you will hear from those frustrated by the current quagmire that is the Middle East.
Let's hope it doesn't come to that. Once you start trying to solve problems by erasing countries from the map, you never know where it will stop.
• Kirk Caraway is editor of nevadapolitics.com, and also writes a blog on national issues at kirkcaraway.com.