An independent kingdom for much of its long history, Korea was occupied by Japan beginning in 1905 following the Russo-Japanese War. Five years later, Japan formally annexed the entire peninsula. Following World War II, Korea was split with the northern half coming under Soviet-sponsored communist control. After failing in the Korean War (1950-53) to conquer the US-backed Republic of Korea (ROK) in the southern portion by force, North Korea (DPRK), under its founder President KIM Il Sung, adopted a policy of ostensible diplomatic and economic "self-reliance" as a check against outside influence. The DPRK demonized the US as the ultimate threat to its social system through state-funded propaganda, and molded political, economic, and military policies around the core ideological objective of eventual unification of Korea under Pyongyang's control. KIM Il Sung's son, KIM Jong Il, was officially designated as his father's successor in 1980, assuming a growing political and managerial role until the elder KIM's death in 1994. Under KIM Jong Il's rein, the DPRK developed nuclear weapons and ballistic missiles. KIM Jong Un was publicly unveiled as his father's successor in 2010. Following KIM Jong Il's death in 2011, KIM Jong Un quickly assumed power and has since occupied the regime's highest political and military posts. After decades of economic mismanagement and resource misallocation, the DPRK since the mid-1990s has faced chronic food shortages. In recent years, the North's domestic agricultural production has increased, but still falls far short of producing sufficient food to provide for its entire population. The DPRK began to ease restrictions to allow semi-private markets, starting in 2002, but has made few other efforts to meet its goal of improving the overall standard of living. North Korea's history of regional military provocations; proliferation of military-related items; long-range missile development; WMD programs including tests of nuclear devices in 2006, 2009, 2013, 2016, and 2017; and massive conventional armed forces are of major concern to the international community and have limited the DPRK's international engagement, particularly economically. In 2013, the DPRK declared a policy of simultaneous development of its nuclear weapons program and economy. In 2018, KIM Jong Un declared the North's nuclear weapons development complete, announced economic development as a leading priority, and increased diplomatic engagement. He participated in three 2018 inter-Korean summits with ROK President Moon Jae-in and in two with US President TRUMP (in 2018 and 2019).