Well, now that immigration reform might carry with it a much more technologically sophisticated wall to keep barbarians out (yay drones!), are there any lessons we can glean from history to tell us if this is actually a good idea or not?
Of course there are.
First off, I'd like to just say before we even begin discussing this topic that I think the entire debate over illegal immigration makes absolutely no sense. Republicans, conservatives, and their centrist allies have yet to make a case as to why Mexicans and Central Americans coming into this country is actually a negative thing (and of course, this debate is about Latinos coming into this country, not Swedes). They just basically assume it is bad and then operate from that assumption. Republicans fearing the loss of White America is one thing. I get that. Don't agree, but it makes sense. But, immigrants can bring a lot of positive things to the community. They bring rusted out, dead cities back to life by owning businesses and doing the jobs Americans don't really want to do anymore (fair wage and labor rights implied here people). If someone wants to come to America and work hard and raise a family, then why are we standing in their way? We didn't do that when poor European serfs from Eastern Europe and god knows where else came here and did the same thing. Oh wait, they were White. The drug connection is because of our idiotic drug laws, so we are the ones to have to take responsibility for that.
But I digress. The Great Wall.
Well, the Great Wall was a symbol of the demarcation of Chinese culture, which was seen by the Chinese as the greatest, most sophisticated, and envy of the world, and everybody else who wasn't Chinese and therefore inferior. The problem here, as is the problem with all ideologies that say that belonging to ethnicity A means that all non ethnicity A's are inferior for no good reason, is that the Chinese would get invaded and be forced to concede that they were homo sapiens sapiens too. Sometimes they'd win sometimes they'd lose. When they did get invaded, Chinese culture would come under attack. China has always had a mix of cultures surrounding it. People of different religions, ethnicities, and cultures coming in and out paying tribute or just trying to get where they were going. China had a lot of enemies and a lot of frenemies. But that's the way empires go.
The Great Wall was not all that effective at keeping people out, but it had it's moments. It worked to slow invaders so that your city walls could do their thing. Unless your opponent had siege weapons. That sucked. You cannot say it was 100% ineffective or effective, it just depending on what was going on at the time. And good sky god was it expensive. Not just in terms of building materials and money, but in the human cost in the number of corvee laborers who died while building the wall. We'll never know the exact number, or even an estimate of how many people died building this thing, but it was a lot. Hundreds of thousands, easy. And the expense was not entirely up front. The wall had to be maintained, lest parts of it were to crumble. You had to hire soldiers to man it, and they had to be paid enough to actually want to do their jobs. Remember, Qin Shi Huang cannot call you up on his cell phone and make sure you're watching out for the Jurchens. After Qin Shi Huang, the wall would be rebuilt, but it would cost a lot and the mood of the people could turn on you if you send too many of their sons to die in prison camps building your wall.
"So what does the Great Wall have to do with today?" you may be asking. "It won't take as many people to properly man our Great Wall of Mexico, we have drones to survey the area. Building it won't cost human lives, and even if it did, it would be on nowhere near the scale of the Great Wall of China." That's true, but it will still cost you a metric crap ton of money to build, and the maintenance is a steep check you'll have to pay every year. You'll divert tons of resources in terms of man power, automation or no automation, which is man power that could be used for other pursuits that could just as effectively defend your country. Also, bribery and lawlessness on the border still occur. Do you want far right, proto-fascist minutemen patrolling the border, using Mexicans as target practice? The penalty for illegal immigration is death now? Secondly, I mean, the Great Wall actually had a military dimension to it. The Chinese were being invaded by nomadic tribes that would come in and kill people and take the riches of the Chinese empire. We're afraid that someone might come into our country and use public schools. More educated people in the world. The horror.
Wait a second.
Could the Chinese have done something different themselves? Did they have to kill off millions of their own people, use an untold amount of resources, bankrupt themselves in some cases, and live in constant fear, or could they have handled the situation differently? What if they treated the nomadic peoples and the non-Chinese, not as inferior barbarians that need to be subject to Chinese ego stroking...erm...I mean the tribute system, but as trade partners and people who were of a different culture, but not necessarily inferior? After Mongolia was annexed during the Qing dynasty, the native nomadic cultures simply integrated to some extent (although not fully, even today). The PRC now makes attempts to share in the wealth of the coal mining boom in inner Mongolia with the peoples there, rather than push them out of the main polity and wonder why they try to force themselves in.
I'm not naive enough to think humanity at any stage of its development would have no war, but if China had simply accepted that its geographical position came with the fact that people who were hungry and starving would come around every once in awhile, that they could use their technological prowess to make everyone's lives better. This same mindset might have spared the Romans from feeling the heel of the Visigoths on their necks.
Ah well, wishful thinking. Great Wall of Mexico it is.