For two decades an old US naval base in Puerto Rico languished in weeds and rust. Then the fighter jets roared in.
 
  
As the Trump administration expands an anti-drug offensive off the coasts of Venezuela and Colombia, it’s leaning on small Caribbean islands like Grenada and Trinidad and Tobago for logistical support. The deployment is turning economically vulnerable nations into uncomfortable accomplices in a mounting US drug war with no clear end game.
Nowhere is the tension more evident than in the US territory of Puerto Rico, where most of the 10,000 troops now in the Caribbean ...