President Trump's tweet this morning, suggesting Middle Eastern migrants have joined the large caravan of mostly Central Americans, is more likely than not true. Whether any are linked to terrorism is an altogether separate question he did not address, because this is a very hard thing to ever know with this traffic. A significant homeland security conundrum regarding Middle Eastern migrants moving along well established smuggling routes through Latin America is that we don't and often can't know their hearts and personal histories; often they travel with fake or no ID.

Sadly, it looks like Mexico's Police and Military are unable to stop the Caravan heading to the Southern Border of the United States. Criminals and unknown Middle Easterners are mixed in. I have alerted Border Patrol and Military that this is a National Emergy. Must change laws! — Donald J. Trump (@realDonaldTrump) October 22, 2018

An excerpt from my most recent blog post about this — which casts doubt on a claim by Guatemala President Jimmy Morales about apprehending 100 Middle Eastern migrants linked to terrorism — explains why I can comfortably support the president's contention this morning and feel relieved that he has finally acknowledged the threat issue:

It is well established that migrants from origin "sending" countries the United States regards as national security concerns — due to the presence of Islamist terrorist groups in them — have for many years routinely traversed Guatemala on their way to the U.S. southern border. U.S. homeland security authorities have dubbed migrants like this "special interest aliens" (SIAs), as explained in this Center for Immigration Studies Backgrounder, and elaborated on here, here, here, and here. Syrian migrants have been caught in Central America and at the Texas and California borders, and some special interest alien migrants caught in Central America were linked to terrorist networks; Reuters reported last year about a Somali named Ibrahim Qoordheen who was apprehended in Costa Rica and who was reputed to have been on the U.S. terror watch list. That some are linked to terrorist organizations is in the realm of likelihood.

I have been to Guatemala to report about this particular smuggling traffic. The country is literally a superhighway for human smuggling of people from all over the world, including the Middle East. As a journalist in 2007, I traveled throughout Guatemala tracing their paths and interviewed numerous current and former government officials there about the Middle Easterners, Somalis, Pakistanis, and others coursing through toward Mexico. I also once visited a Guatemalan consular office in Amman, Jordan, where Iraqi refugees told me their human smugglers were sourcing visas for about $700 each.