Metro Line M4 (Budapest Metro) Metro Line M4 (Budapest Metro) Line 4 (officially: South Buda–Rákospalota (DBR) Line, Metro 4 or M4, and unofficially: Green Line), is the fourth line of the Budapest Metro. It opened on 28 March 2014. The first section, 7.4 km in length and consisting of ten stations, connects the southwestern Kelenföld vasútállomás located in Buda, and the eastern Keleti pályaudvar in Pest, under the River Danube. While three additional sections — one an eastern extension to Bosnyák tér, the second west to Virágpiac, and a third further east to Újpalota — have been planned, these remain unfunded by the Budapest city
Budapest Memorandum on Security Assurances or political independence of Ukraine, Belarus and Kazakhstan. As a result, between 1994 and 1996, Belarus, Kazakhstan and Ukraine gave up their nuclear weapons. Before that, Ukraine had the world's third largest nuclear weapons stockpile, of which Ukraine had physical if not operational control. The use of the weapons was dependent on Russian-controlled electronic Permissive Action Links and the Russian command and control system. Following the annexation of Crimea by the Russian Federation in 2014, the US, Canada, the UK, along with other countries, stated that Russian involvement was a breach of its obligations to Ukraine under the Budapest Memorandum,