South Korea maintains a unitary presidential republic under the 1987 constitution with a unicameral legislature, the National Assembly. It is considered a regional power and a developed country, with its economy ranked as the world's fourteenth-largest by nominal GDP and the fourteenth-largest by GDP (PPP). Its citizens enjoy one of the world's fastest Internet connection speeds and densest high-speed railway networks. The country is the world's ninth-largest exporter and ninth-largest importer. Its armed forces are ranked as one of the world's strongest militaries, with the world's second-largest standing army by military and paramilitary personnel. In the 21st century, South Korea has been renowned for its globally influential pop culture, particularly in music, TV dramas, and cinema, a phenomenon referred to as the Korean Wave. It is a member of the OECD's Development Assistance Committee, the G20, the IPEF, and the Paris Club.