Driving along certain parts of our southwest border with Mexico, there is no question that there is a dividing line between our two countries. South of San Diego between San Ysidro and Otay Mesa, California, lies an 18 foot-high steel mesh fence topped with razor wire. This fence sits about thirty yards to the north of a rusted-out decades-old airport landing mat fence riddled with holes. In between the two is a paved road for US Border Patrol vehicle access and tall poles affixed with cameras and stadium lighting. In the mountainous parts of this sector where this setup isn’t physically possible, Border Patrol agents lie in wait for illegal immigrants and drug smugglers.

Elsewhere along the border, the international boundary is blocked off by a brown steel bollard fence that stretches for dozens of miles through the southwestern Arizona desert, or multiple reinforced mesh and chain-link fences that separate El Paso, Texas from Ciudad Juárez, Mexico. Border Patrol agents rove along the fence and open stretches of the border in SUVs, on all-terrain vehicles, by helicopter, and even on horseback. Highway checkpoints manned by agents can be found along several US highways dozens of miles north of the actual border, and the agency’s telltale white and green trucks can be spotted driving around numerous border cities and towns.

It’s relatively easy to see why some people might view these things as a sign that our borders have been ‘militarized,’ which is a term being used more commonly by those on the left, and occasionally even by those on the right. But is the increased presence of the Border Patrol in border communities really akin to a heavy-handed paramilitary presence, or a true necessity in order to secure our borders and protect our communities from violent drug smugglers and human traffickers?

The key to digging into this question is to take a look at other international boundaries and the measures the countries on each side are taking to either keep outsiders out–or keep their own people in. Probably the clearest example of a truly militarized border would be the boundary and accompanying demilitarized zone (DMZ) between North and South Korea. The border between the two countries–who are technically still at war with each other–extends 160 miles, and the DMZ is 2.5 miles wide. It’s ironic that it’s called a demilitarized zone because there is a huge military presence, and the border area is filled with landmines, razor wire fences, and military troops on both sides. The tension between the two countries along parts of the DMZ is tangible, and the measures being taken to keep the two separate are almost unfathomable to most Americans.

Another example of a militarized separation between countries is the various barriers Israel maintains with its neighbors. There is a partially completed border wall between Israel and the West Bank, a multi-layered barrier between Israel and the Gaza Strip, and a fortified fence with concertina and razor wire, touch sensors, motion detectors, infrared cameras and ground radar along the border with Golan Heights and in the north with Lebanon. The Line of Control–known as Asia’s Berlin Wall–between India and Pakistan in the region of Kashmir was called “the world’s most dangerous place” by former President Bill Clinton in 2000. It contains a 340 mile-long barrier, which consists of double-row of fencing and concertina wire eight to twelve feet in height, and is electrified and connected to a network of motion sensors, thermal imaging devices, lighting systems and alarms.

The logistics of these barriers have many things in common with our southwest border, which is probably why some choose to view it as being militarized, but there are many significant differences. First, the countries on either side of those examples are at war with each other in some way. While occasionally strained, we as a country have a very good relationship with the government and people of Mexico. These other countries don’t have a billion dollars worth of commerce crossing their borders every day in both directions, just as we don’t have terrorists from Mexico or Canada launching rockets into Arizona and Texas. While the US Border Patrol certainly has a large presence on our borders (and some would say not large enough), they are still a law enforcement agency with only arrest powers. Our military is expressly prohibited from engaging in the enforcement of civilian laws by virtue of the Posse Comitatus Act, which means they cannot have an active presence on our borders. During the years our National Guard troops were assigned there, they acted in a support role only, providing extra eyes and ears, intelligence analysis, and civil engineering assistance.

Another difference between the nature of our border security strategy and those examples is that we’re defending against a largely criminal problem, whereas those countries are dealing with conventional and active terrorist threats. We are not in conflict with the Mexican or Canadian armies, and the flow of illegal immigrants and drugs generally goes in just one direction at our southern end. We don’t shoot illegal crossers on sight as we might enemy combatants in a traditional war zone; they are apprehended and placed into either criminal or removal proceedings.

But this doesn’t mean that protective measures along our borders aren’t warranted. We are attempting to defend 2,000 miles of border in the south and 5,500 miles of border in the north, which is nowhere near what other countries have attempted to do. There is simply no way to detect and apprehend so many violent criminals and illegal immigrants across so much territory without some kind of barrier system, border technology, and the deployment of thousands of law enforcement officers in places where the cross-border traffic is highest. Many on the left may view this as a militarization of our borders, but those critics should question what the alternative solution would be.

Follow Sylvia Longmire on Twitter @DrugWarAnalyst