In 2010, two more major incidents with North Korea would occur under the Obama Administration: the sinking of a South Korean Navy Ship that actuated new rounds of military exercises with South Korea as a direct military response to sinking and the Bombardment of Yeonpyeong prompting the US Navy aircraft carrier to depart for joint exercises in the Yellow Sea with the Republic of Korea Navy, in part to deter further North Korean military action. In light of the geopolitical developments with North Korea, the Obama Administration has dubbed the U.S.-South Korean alliance as a "cornerstone of US security in the Pacific Region."