Background: Sven Anders Hedin, KNO1kl RVO, (19 February 1865 - 26 November 1952) was a Swedish geographer, topographer, explorer, photographer, travel writer, and illustrator of his own works. During four expeditions to Central Asia, he made the Transhimalaya known in the West and located sources of the Brahmaputra, Indus and Sutlej Rivers. He also mapped lake Lop Nur, and the remains of cities, grave sites and the Great Wall of China in the deserts of the Tarim Basin. In his book Fran pol till pol (From Pole to Pole), Hedin describes a journey through Asia and Europe between the late 1880s and the early 1900s.
Context: Hedin was a monarchist. From 1905 onwards he took a stand against the move toward democracy in his Swedish homeland. He warned of the dangers he assumed to be coming from Czarist Russia, and called for an alliance with the German Empire. Therefore, he advocated a strengthened national defence, with a vigilant military preparedness. August Strindberg was one of his opponents on this issue, which divided Swedish politics at the time. In 1912 Hedin publicly supported the Swedish coastal defense ship Society. He helped collect public donations for the building of the coastal defense ship HSwMS Sverige, which the Liberal and anti-militarist government of Karl Staaff had been unwilling to finance. In early 1914, when the Liberal government enacted cutbacks to the country's defenses, Hedin wrote the Courtyard Speech, in which King Gustaf V promised to strengthen the country's defenses. The speech led to a political crisis that ended with Staaff and his government resigning and being replaced by a non-party, more conservative government.  He developed a lasting affinity for the German empire, with which he became acquainted during his formal studies. This is also shown in his admiration for Kaiser Wilhelm II, whom he even visited in exile in the Netherlands. Influenced by imperial Russian and later the Soviet union's attempts to dominate and control territories outside its borders, especially in Central Asia and Turkestan, Hedin felt that Soviet Russia posed a great threat to the West, which may be part of the reason why he supported Germany during both World Wars.  He viewed World War I as a struggle of the German race (particularly against Russia) and took sides in books like Ein Volk in Waffen. Den deutschen Soldaten gewidmet (A People in Arms. Dedicated to the German Soldier). As a consequence, he lost friends in France and England and was expelled from the British Royal Geographical Society, and from the Imperial Russian Geographical Society. Germany's defeat in World War I and the associated loss of its international reputation affected him deeply. That Sweden gave asylum to Wolfgang Kapp as a political refugee after the failure of the Kapp Putsch is said to be primarily attributable to his efforts.
Question: Why did he think that they posed a threat?. Whats the answer?
Soviet union's attempts to dominate and control territories outside its borders, especially in Central Asia