Russia is a large country. Its land is mostly flat. This makes defending its borders (where no mountains or natural obstructions exist) a difficult task. It is expensive to build infrastructure in Russia. Its extreme climate makes poorly built roads break more often.
The United Kingdom is a small island with a mild climate and access to warm water ports. It is easy to defend because any foreign country has to cross a body of water to attack. In addition, since it is small and warm the cost of construction is cheaper than in Russia.