What did Britain view as a threat to their control by Russia and
Germany?

Relations between Russia and Germany...have been a series of alienations, distinguished for their bitterness, and of rapprochements, remarkable for their warmthA cardinal factor in the relationship has been the existence of an independent Poland...when separated by a buffer state the two great Powers of eastern Europe have been friendly, whereas a contiguity of frontiers has bred hostility.[1]

Russia helped liberate Germany in 1812–15 in the Napoleonic Wars, and the two were generally friendly for a century, especially during the time of Otto von Bismarck who established the League of Three Emperors in 1873 with Russia, Germany, and Austria-Hungary. But after Bismarck's dismissal in 1890, his successors chose to support Austria against Russia over competing influence in the Balkans. Germany fought against Russia in World War I (1914–1918). Relations were warm in the 1920s, very cold in the 1930s, friendly in 1939–41,[2] and then turned into war to the death in 1941–45. In the 1920s both countries co-operated with each other in trade and (secretly) in military affairs. Hostilities escalated in the 1930s as the Fascists sponsored by Berlin and the Communists sponsored by Moscow fought each other across the world, most famously in the Spanish Civil War (1936–39). In a stunning turnabout in August 1939, both countries came to an agreement, and divided up the previously independent nations of Eastern Europe. That détente collapsed in 1941 when Germany invaded the USSR. The Soviets survived however and formed an alliance with Britain and the U.S., and pushed the Germans back, capturing Berlin in May 1945.

During the Cold War 1947–1991, Germany was divided, with East Germany under Communist control and under the close watch of Moscow, which stationed a large military force there and repressed an uprising in 1953. Since the end of the Cold War and German reunification, in 1989–91, Germany and Russia have developed a "Strategic Partnership" in which energy is indisputably one of the most important factors. Germany and Russia depend on each other for energy, namely in Germany's need for energy from Russia and Russia's need for heavy German investment to develop its energy infrastructure.

According to a 2014 BBC World Service poll, only 21% of Germans view Russia's influence positively, with 67% expressing a negative view. Russians, however, have a much more positive view of Germany than Germans do of Russia, with 57% viewing Germany's influence positively and 12% negatively.[3]

Relations turned highly negative in 2014 in response to Russia's seizure of Crimea from Ukraine and support for insurgents in Ukraine. Germany was a leader between NATO Quint in imposing round after round of increasingly harsh European Union sanctions against the Russian oil and banking industries and top allies of President Vladimir Putin. Russia responded by cutting food imports from the EU.

explanation:

the answer is the huegonots.