Read this: U.S. President Barack Obama has rarely used the term, but in his inaugural address on 20 January 2009, he stated "Our nation is at war, against a far-reaching network of violence and hatred." In March 2009 the Defense Department officially changed the name of operations from "Global War on Terror" to "Overseas Contingency Operation" (OCO). In March 2009, the Obama administration requested that Pentagon staff members avoid use of the term, instead using "Overseas Contingency Operation". Basic objectives of the Bush administration "war on terror", such as targeting al Qaeda and building international counterterrorism alliances, remain in place. In December 2012, Jeh Johnson, the General Counsel of the Department of Defense, stated that the military fight will be replaced by a law enforcement operation when speaking at Oxford University, predicting that al Qaeda will be so weakened to be ineffective, and has been "effectively destroyed", and thus the conflict will not be an armed conflict under international law. In May 2013, Obama stated that the goal is "to dismantle specific networks of violent extremists that threaten America"; which coincided with the U.S. Office of Management and Budget having changed the wording from "Overseas Contingency Operations" to "Countering Violent Extremism" in 2010.

What did the Defense Department change its name to?
What is the answer? (If it cannot be answered, return "unanswerable")
unanswerable