A declining power can be a dangerous one. Take Russia, whose president, Vladimir Putin, has been engaging in external aggression to excite the patriotism of the Russian people and thus remain popular despite an economy ravaged by low energy prices, corruption and sanctions. Yet even as Russia threatens international peace and Western interests, its weak economy has caused it to fall far behind NATO militarily. Russia’s defence spending is about one-tenth of NATO’s;1 and with energy prices unlikely to rise, this disparity will persist. Moreover, Russia cannot compete with the West in digital technology, which is now the main multiplier of military strength. Knowing this, the Russians have chosen an asymmetric strategy, involving hybrid warfare, deniable intervention, cyber war and nuclear intimidation. They have preyed on neighbouring states by infiltrating paramilitary forces, using agents and proxies, holding menacing military exercises and attacking computer networks; and they have hijacked social media to undermine Western confidence and cohesion. The West has struggled to answer this Russian strategy.

Within its asymmetric strategy, Russia also maintains a preponderance of regional (non-strategic) nuclear weapons, which it is likely to increase through deployments of intermediate-range nuclear forces (INF), legalised by US withdrawal from the INF Treaty. Nuclear weapons have always been a ‘cheap’ option to make up for deficiencies in conventional forces, and Russia has made them a top priority. Russian spending on nuclear weapons increased by 66% between 2010 and 2016, from $5.6 billion in 2010 to $9.3bn in 2016.2