This idea actually originated in Bachelet’s government. It was not envisaged as a Trumpian solution to stop illegal immigration, it was intended to limit the egress of vehicles to Bolivia, where stolen-to-order Chilean SUVs and Pickups are exchanged for drugs. The Bolivian authorities turn a blind eye to this traffic, which is doubly damaging for Chile. I guess the idea was scrapped as too costly, and the military dynamited some of these clandestine entry points instead, with the aim of making them impassible for vehicles.
Once again, the truth is cleverly twisted by the PC, and its depressing to see how their smears go mostly unquestioned, to be repeated even in respected foreign publications. That Economist article recently mentioned is a typical example, and the disinformation that it propagated has now come full circle and is being quoted in the local press.
My motivation in writing the above is not to defend Kast. But I do detest being taken for a fool and lied to so blatantly.