Estonian authorities deployed more than 1,600 reserve military units in an unannounced exercise that is scheduled to start on Wednesday as the illegal immigration crisis in nearby Belarus intensifies. In a statement issued by the government on Nov. 17, the forces summoned include 1,636 reservists from different units, who are mainly engineers that will be strengthening border infrastructure from Nov. 17 until Nov. 25. “The main purpose of exercise OKAS/QUILL is to test the national defense chain of command, from the Estonian Government decision down to the particular units’ combat readiness in the rapid response structure,” the statement reads. The reserve engineers will also work on installing a temporary barrier in border areas that have “previously been used by organized crime to facilitate illegal migration,” officials said. The Estonian police and border guard said in a statement obtained by news agency Reuters that 40 kilometers (about 25 miles) of razor-wire …