Why Was a Russian Attack Sub Lurking in the Gulf of Mexico?

Sen. John Cornyn (R-Texas) asked the country's top naval officer to explain how a Russian sub reportedly lurked around the Gulf of Mexico undetected.

The nuclear-powered attack submarine activity reportedly occurred in June and July, at the same time as incursions into U.S. airspace by Russian strategic bombers.

"If these reports are accurate, the repercussions are serious. It is my understanding that an Akula-class submarine can be armed with an array of weapons, including torpedoes and long-range cruise missiles, capable of destroying both U.S. nuclear submarines and aircraft carriers," Cornyn wrote today to Admiral Jonathan Greenert, chief of naval operations at the Pentagon.

"The submarine patrol, taken together with the air incursions, seems to represent a more aggressive and destabilizing Russian military stance that could pose risks to our national security," he added.

The member of the Senate Armed Services Committee framed the incident as "especially troubling" given the deep cuts President Obama has sought for antisubmarine defense systems.

"In light of the gravity of this situation, I request a detailed explanation of the facts surrounding these reports," Cornyn asked the admiral.

In 2009, a pair of Russian subs patrolling off the East Coast raised concern among defense and intelligence officials.