Question: Rail Baltica is a high-speed rail project to link Poland and the Baltic States with which other northern European country?

Context articles: Naples–Salerno high-speed railway
Rail Baltica
California High-Speed Rail Authority
High-speed rail in Indonesia
Madrid–Galicia high-speed rail line
Hangzhou–Fuzhou–Shenzhen High-Speed Railway
Rio–São Paulo high-speed rail
High-speed rail in Latvia
High-speed rail in China
High-speed rail in Europe

The Naples–Salerno high-speed railway line (also known in Italian as the Linea a Monte del Vesuvio, meaning the "line up Mount Vesuvius") is a link in the Italian high-speed rail network opened in June 2008.
 The 29 kilometre-long line is one of the new high-speed lines being built to strengthen rail transport system in Italy and in particular freight and passenger transport in Campania.
 The line is part of Corridor 1 of the European Union's Trans-European high-speed rail network, which connects Berlin and Palermo.
Rail Baltica (in Estonia known as Rail Baltic) is a project to link Finland, the Baltic States and Poland with a standard gauge rail line, providing passenger and freight service between the countries and improving rail connections between Central and Northern Europe.
 It envisages a continuous rail link from Tallinn (Estonia), to Warsaw (Poland), via Riga (Latvia) and Kaunas (Lithuania).
 It will bypass the Kaliningrad Oblast (Russia) and Hrodna (Belarus), which have historically hosted two Poland–Lithuania rail routes.
 Rail Baltica is one of the priority projects of the European Union: "Trans-European Transport Networks" (TEN-T).
The California High-Speed Rail Authority (CHSRA) is a California state agency established pursuant to the California High-Speed Rail Act (S.B. 1420, Chapter 796 of the California Statutes of 1996) to develop and implement high-speed intercity rail service, such as the California High-Speed Rail project.
Plans and studies have been in the works for high-speed rail (HSR) in Indonesia since before 2010.
 A new plan to build a HSR was announced by Indonesian Government in July 2015.
 Indonesia's first – and possibly also Southeast Asia's first – high-speed rail project was expected to connect the national capital Jakarta with Bandung in neighboring West Java province, covering a distance of around 140 kilometres.
 Plans were also mentioned for a possible later extension of the HSR to Indonesia's second largest city, Surabaya in East Java.
The <dfn>Madrid–Galicia high-speed rail line</dfn> is a high-speed railway line partially open in Spain that will link the city of Madrid with the region of Galicia via the cities of Olmedo, Zamora and Santiago de Compostela when completed.
 The line will also connect the Atlantic Axis high-speed rail line to the rest of the Spanish AVE high-speed network.
 The Madrid–Galicia high-speed rail line is being constructed as double electrified line and is designed for trains running at speeds up to 350 km/h .
The Hangzhou–Fuzhou–Shenzhen High-Speed Railway (杭福深高速铁路 formerly 东南沿海快速通道 or 东南沿海铁路) refers to the dual-track, electrified, high-speed rail lines (HSR) in service along the southeastern coast of China, which links the Yangtze River Delta on the East China Sea and Pearl River Delta on the South China Sea.
 It is one of the eight arterial high-speed rail corridors that form the backbone of China's HSR network.
 The southeast coast is the only region of high-speed rail construction where no previous conventional railroads existed.
 Hence, the high-speed rail lines built on the southeast coast will, for the most part, carry both passenger and freight traffic, and will not be passenger-dedicated lines that comprise most of the other HSR corridors in China.
The Rio–São Paulo High-Speed Rail (Portuguese: "Trem de Alta Velocidade Rio-São Paulo" ; Abbreviation: "TAV RJ-SP") is a planned high-speed rail project to connect São Paulo and Rio de Janeiro.
 While originally planned to be operational by 2014 in time for the 20th FIFA World Cup to be held in Brazil at a cost of $9 billion, as of May 2015 formal bidding for the project had yet to start, with the Brazilian government delaying the auction by "at least" one year in August 2013, pushing back hopes of completion to at least the 2020s
Current plans call for a high-speed Rail Baltica that will connect the Latvian capital Riga with Pärnu and Tallinn to the north and with Kaunas and Warsaw to the south.
 Reports in March 2011 indicate plans are moving towards a standard gauge railway.
High-speed rail (HSR) in China is officially defined as passenger-dedicated railways designed to carry multiple unit trains at speeds of 250-350 km/h .
 Certain mixed use freight and passenger rail lines, that can be upgraded for train speeds of 250 km/h, with current passenger service of at least 200 km/h , are also considered high-speed rail.
 The country's HSR network, which in 2016 extended to 29 of the country's 33 provincial-level administrative divisions and exceeded 22,000 km in total length, accounted for about two-thirds of the world's high-speed rail tracks in commercial service.
 The world's longest HSR network is also the most extensively used, with 1.44 billion trips delivered in 2016.
High-speed rail is emerging in Europe as an increasingly popular and efficient means of transport.
 The first high-speed rail lines in Europe, built in the 1980s and 1990s, improved travel times on intra-national corridors.
 Since then, several countries have built extensive high-speed networks, and there are now several cross-border high-speed rail links.
 Railway operators frequently run international services, and tracks are continuously being built and upgraded to international standards on the emerging European high-speed rail network.
 In 2007, a consortium of European railway operators, Railteam, emerged to co-ordinate and boost cross-border high-speed rail travel.
 Developing a Trans-European high-speed rail network is a stated goal of the European Union, and most cross-border railway lines receive EU funding.
 Several countries — France, Spain, Italy, Germany, Austria, Sweden, Belgium, the Netherlands, Russia and the United Kingdom — are connected to a cross-border high-speed railway network.
 More are expected to be connected in the coming years as Europe invests heavily in tunnels, bridges and other infrastructure and development projects across the continent, many of which are under construction now.
 Alstom was the first manufacturer to design and deliver a high speed train or HS-Train, which ended up in service with TGV in France.
 Currently, there are a number of high-level manufacturers designing and building HSR in Europe, with criss-crossed alliances and partnerships, including Canadian company Bombardier, Alstom itself, the Spanish Talgo and the German Siemens.