 Panama's proximity to Colombia and their thriving off-shore banking industry has lured many traffickers to use that nation and Haiti as bases for their activities.Citizens of the Dominican Republic also require visas to visit Haiti, not only due to the hostile, sometimes volatile relations between both nations, but also because since the late 1990s, the Dominican Republic has become another base for illicit drugs bound for the United States, which usually enter illegally via Puerto Rico.Once in Puerto Rico, drugs can easily reach the United States due to the absence of both immigration and customs between that island and the mainland.