The monroe doctrine is dead under Obama and we are in more and more danger every day. Breaking news....Iran just shipped long distance missiles to Venezuela that can reach us! The liberal media says nothing and Obama does nothing.
Here a my very brief take on this. Having studied in the US, I'm quite familiar with your / our history. For enlightening purposes, I quote: "The Monroe Doctrine is a policy of the United States introduced on December 2, 1823. It stated that further efforts by European nations to colonize land or interfere with states in North or South America would be viewed as acts of aggression requiring U.S. intervention"
The US returned the territories occupied by the Armed Forces in 2000. Nevertheless, in the Torrijos-Carter Treaty there's a clause that states that the US can "invade" (I apologize for not having the quote) Panama if there's a thread to the Canal. Now, it is impossible to "defend" the Canal, just like you could not "defend" the Mississippi or the Nile river. Thus, it has been plain from the start that that specific clause is intended as an apology for military purposes.
So, you see, the Monroe Doctrine is alive and kicking!
In two years the Canal will have it's 100 B-day, and the new set of locks (so that the Post-Panamax ships will be able to transit) will be inaugurated.
Talk about a small country stuck between a rock and a hard place!