President Trump is blaming nearly everyone for the migrant caravan wending its way to the United States: Democrats, Mexico, the home countries of these Central American asylum seekers.

Perhaps it's time he looked in the mirror. Because the country he leads is very culpable.

American deportation policies combined with the Cold War rivalry between America and the Soviet Union have destabilized Central America and turned it into an unlivable hellhole. But instead of taking responsibility and making amends, Trump is feeding hysteria in a bid to rally his base ahead of the midterm elections.

The caravan has dwindled from 7,000 migrants at its peak to just a few thousand now. And, if a similar caravan in the summer is any indication, it will shrink even more by the time it reaches the U.S. in December. But that hasn't stopped Trump from dialing up the panic level.

He has denounced Democrats as "weak" on immigration and, in addition to the National Guard, called up the military to help beef up border security. As if that is not enough protection against what is mostly a procession of helpless women and children, he is now threatening to use his emergency powers to seal the southern border entirely and ban entry without offering any of them asylum hearings, something that the U.S. is legally required to do. He has also threatened to cut off aid to Honduras, Guatemala, and El Salvador, the Northern Triangle countries whose residents make up the bulk of the caravan.

But let's examine for a moment why exactly these people are fleeing their homelands and making the dangerous, thousands-of-miles-long schlep on foot to America in the first place.

It is not because they are gullible fools marching to the tune of left-wing Honduran politicos hell-bent on challenging American sovereignty, as the right-wing media narrative has it. (Sadly, even the pro-immigration Wall Street Journal has fallen for this line.) It is also not because liberal billionaire George Soros, the right's all-purpose boogeyman, is paying them to storm America, as implied by fake pictures of migrants accepting dollar bills that spread like wildfire on social media.

The real story begins during the Cold War in the late 1970s and early 1980s, when the United States and the Soviet Union turned these three countries into an ideological battlefield. Cuban dictator Fidel Castro started funneling Soviet weaponry and money to not just prop up Nicaragua's left-wing Sandinista regime, but also to use that country as a launching pad for a broader regional insurgency to topple the right-wing governments in its three neighbors, as University of Virginia's John Norton Moore has written. President Ronald Reagan, eager for a showdown with the Evil Empire, responded in kind, funding the Contra insurgency against the Nicaraguan Sandinistas and paramilitary operations to prop up the U.S.-friendly regimes of El Salvador, Honduras, and Guatemala.

The upshot was civil war and a complete social breakdown from which these countries have never recovered.

As Princeton's Doug Massey noted at a recent immigration conference (that I co-organized on behalf of Reason Foundation), in the 1960s, the GDP of these "frontline countries" was equivalent to those of "non-frontline states" such as Costa Rica, Belize, and Panama. Now the latter cohort's GDP is almost three times greater. Likewise, while the homicide rate of non-frontline states is 19.7 per 100,000, it is 43.5 per 100,000 for the frontline states. San Pedro Sula, the Honduran city where the caravan started, has become the murder capital of the world.

Prior to Reagan's intervention, migration from Central America was negligible. Post-intervention, it shot up, although it never reached beyond 375,000 undocumented migrants from these countries living in America. Right now, at 150,000, it is at a relatively low ebb, although youā€™d never guess that from Trump's broadsides against the "millions" who want to "break our laws, violate our borders, and overwhelm our nation."

To make matters worse, Massey points out, although Reagan offered mass asylum to Nicaraguans flocking to America because they were fleeing an enemy nation, he refused to extend the same courtesy to immigrants from these frontline nations because their regimes were friendly to America and therefore, by definition, not oppressive ā€” never mind their massive human rights abuses!

The upshot was that while Nicaraguans got permanent residency in America, Hondurans, Guatemalans, and El Salvadorians were consigned to life as unauthorized immigrants. Also, although there were far more Mexicans who were similarly unauthorized, they came to America not to flee violence and persecution but for better economic opportunities. That, combined with the support Mexicans received from established networks of families and friends who had been migrating to America for generations, allowed them to make an honest living here (which is why crime rates in border towns like El Paso with a large unauthorized Mexican population are among the lowest in the country).

Not so for Central American migrants, who had literally no local support. Their destitution and desperation spawned gangs like MS-13 that Trump is now using to scare Americans.

Barack Obama is hardly blameless. He poured fuel on the burning Central American subcontinent when he mass deported some 161,000 gang members and other criminals back to these countries. "[Sending] such a large number of criminals, many of them violent gang members, into countries with relatively small populations, proved to be extremely destabilizing," Massey says. It turned these countries into even bigger cauldrons of conflict and violence where daily life for ordinary people became impossible. Many migrants in the caravan recount heart-wrenching stories of family members being harassed, kidnapped, beaten, and killed because they refused to join the gangs or succumb to extortion.

The U.S. is responsible, at least in part, for the mess in these countries. We ought to be sending planes to evacuate their residents ā€” not greeting them with boots and bayonets.

America is the richer for doing the right thing when it welcomed over half a million fleeing boat people after the Vietnam War. It can't let a president motivated purely by his poll numbers and no sense of compassion or responsibility shy away from its moral responsibility in the face of a far smaller challenge now.