Sometimes, simpler is better — even in war and counterterrorism. Who would have guessed that a secret weapon in the fight to defeat terrorists and insurgents would turn out to be ... the mundane cell phone?

As a general rule, insurgents worldwide don't much like the sight of a civilian holding a cell phone. All it takes is one quick phone call, and here comes the cavalry.

Rebel groups take the threat so seriously that they often seize all cell phones when they enter a village. If they miss just one, it could mean game over.

In most rural areas of Afghanistan, there are no landline phones or shortwave or any way other devices to communicate quickly. So Taliban militants, who rely on poor communication in rural areas, have recently been attacking cell phone facilities and confiscating phones, stripping locals of the chance to alert U.S. soldiers to their movements.

This provides a huge advantage to the Taliban, because it means that locals, from villagers to shepherds, cannot report their activities fast enough to have an effect.

But Taliban combat units ranging from a few dozen to a few hundred armed men are issued satellite phones, giving them a key tactical advantage.

Peacekeepers have learned that providing local citizens with a simple cell phone is an excellent tool in the fight against extremists and insurgents. An emergency number is distributed to peacekeepers that can transform a humble cell phone into a "bat phone" capable of sending an SOS to soldiers.

In North Korea, a non-governmental organization has launched a successful campaign against leadership by sneaking cheap radios into the country. For ages, only radios that receive one state-approved station have been permitted in the country. "Normal" radios have been illegal, since they could receive Chinese and South Korean programming that is not in the best interests of the North Korean government.

Military personnel and sites like Security Page have also reported that a plan of action similar to the underground pipeline of radios to North Korea is on the table for Afghanistan, where the U.S. military would drop cheap cell phones that could also receive radio broadcasts in Taliban-dominated areas.

U.S. psychological operations aircraft or blimps would transmit programming that these cell phones can receive — weather reports, health and farming updates, religious messages from moderate imams and local and national news.

These cell phones also would be able to dial out — but only to a 911 equivalent manned by Afghan police.

The idea is, "If you hear something or see something, let the good guys know."

Have you heard of the program in the U.S. where old cell phones are modified to call only 911 and given away to make sure people have access to help? Same idea here.

Simple, but smart. Arming civilians with cell phones could save not only the lives of locals, but the lives of our soldiers.

Allison Barrie consults at the highest levels of defense, has travelled to more than 70 countries, is a lawyer with four postgraduate degrees and now the author of the new book "Future Weapons: Access Granted"  covering invisible tanks through to thought-controlled fighter jets. You can click here for more information on FOX Firepower columnist and host Allison Barrie and you can follow her on Twitter @allison_barrie.