Why did they apparently have so little air or intelligence muscle to protect them in the first place? We could get a final answer after the completion of a Benghazi-style after-action probe by the United States Africa Command, or AFRICOM.But what already seems likely is that at least some of the blame lies with those who set in motion a bewildering series of actions. The timeline begins on September 24, when the Trump administration suddenly and inexplicably added Chad to the list of countries whose citizens would be included in the latest iteration of the president's travel ban. Chad and its leaders were utterly blindsided as there was no sense whatsoever that this nation has harbored or even encouraged terrorists — certainly no more culpable than such nations as Iraq, Pakistan, Sudan, or for that matter Chad's neighbors Mali, Niger and Nigeria, none of which were included on this list. Au contraire, Chad's troops have for some time served as an effective ally in the region — the best fighting force deployed in nearby Niger and Mali, with the best intel and best-trained warriors. They were the best because they were trained by the French and its redoubtable Foreign Legion. I know, because I was there in Chad in 1983 when the French had to send in their forces to backstop them when they thought Libya's Moammar Gadhafi might invade from the north.Over the next 30 years, the French turned them into a first-rate fighting force, utterly allied to the Western anti-terrorist effort in the Sahel — itself a desperately critical part of the success of our war against ISIS and against the spread of Islamic terrorism that is threatening to overrun Africa. If the Pentagon and National Security Council have been searching for the next place where, hydra-like, a post-Raqqa ISIS might rise, they need look no further than here. Chad, Mali and Niger offer a central conduit from north African nations like Libya — quite rightly a fellow member of the Trump travel ban, and potentially the richest recruiting lode for Islamic jihad — to the vastly populous regions of Nigeria and its neighbors. Already, Nigerian-based Boko Haram, a proto-Islamic group comprised more of heavily-armed thugs than confirmed jihadis, has made enormous inroads in this region. Now, ISIS is knocking on the door. Some determinedly anti-jihadist nations like Chad, have stepped up to block these efforts. And then Trump went and insulted them. In fact, the September 24 action was only the latest backhanded and ill-informed insult. It seems that US Homeland Security gave all countries 50 days to meet a "baseline" of security conditions, including producing a counterfeit-proof version of their passport to prove that they were reliable enough to allow their citizens into America. But Chad, desperately poor, had quite simply run out of passport paper. They reportedly offered to provide a pre-existing sample of this type of passport. No dice. The next thing they knew they were on the banned list, alongside their arch enemy Libya and other clearly terrorist-driven nations. Barely a week after the announcement of the new travel ban, the Chadian government suddenly began pulling hundreds of their fighters from Niger. There was no immediate explanation, though the nation's communications minister Madeleine Alingué condemned the Trump administration's unheralded move, observing that it "seriously undermines" the "good relations between the two countries, notably in the fight against terrorism." Hard to be more direct than that. Troops from Niger and Mali were now all that now stood between the forces of ISIS and Boko Haram and our own military."We have about 1,000 [American] forces distributed over the Chad Basin, most of them in Niger, but not all of them," Lt. Gen. Kenneth McKenzie, a senior official of the Joint Chiefs of Staff said at a news conference held after the soldiers were ambushed. Indeed, the United States not only has hundreds of troops but also a major drone operation in Niger, something McKenzie failed to mention. But now, Chad's troops, one of the major components of the multinational force in Niger, are largely gone. They had been assembled to patrol, defend and especially to understand this vast stretch of largely barren desert that includes Mali and Niger — a combined territory nearly four times the size of Texas. Few could understand it better or be better equipped to fight there than the army of Chad. I've seen that first-hand. Donald Trump has not. Inexplicably, though, we still sent our small, under-armed band of troops into harm's way. Fifty jihadis, heavily armed with rocket-propelled grenades and machine guns, utterly outgunned and outmanned the slim American force they ambushed. And then our boys died there. The backstory is frightful — filled with mindless decisions executed with minimal knowledge and catastrophic results. It's urgent that we uncover quickly just what led to this terrible disaster. Mr. President, you must see it as your highest priority to find out what or who is really behind the deaths of these four heroic young men.