The United States has absolutely nothing to gain from this unless Al Qaeda opened up shop there. The Cold War is over and so are the "good times" and government cheese..
Speaking of government cheese, Puerto Rico can't be compared. They have been given the right to vote their own future by the US congress and Puerto Ricans are currently undecided between independence, Statehood or status quo. Congress even defeated a bill which would require PR to adopt English as its official language as a condition of Statehood.
Congress approves referendum on future of Puerto Rico - USATODAY.com
If they chose Statehood, Puerto Rico would immediately gain 6 seats in the House of Representatives (currently only 1 "shadow" congressman), 2 Senate seats, popular vote in Presidential elections and matching federal funding for schools, transportation, etc. but the downside is that they'd have to start paying Federal Income Tax and federal aid to dependent children would be cut and left to the State.
The way the federal budget is looking right now it would be in the best interest of the US to divest itself from a fully independent Puerto Rican nation.
Freedom ain't free.