The Prussian military strategist Clausewitz famously said something along the lines of ‘war is a continuation of politics by other means’, and his distinction is still made in the 21st century with the difference between ‘hard power’ and ‘soft power’. Estonia’s claims today that they have been under cyber-attack from the Russians for the past three weeks, if true, suggest that the Russians are developing a ‘third way’ between the two.

These days hard power (military force) is expensive, and potentially catastrophic if used too close to home. Soft power (diplomacy) is slow, and usual requires that your case has some degree of moral traction.

The Russian innovation has been the concerted use of infrastructure and networks to apply pressure on its neighbours. The only difference in kind between the alleged cyber-attack on Estonia this month and the shutting off of gas to the Ukraine last year is that one is more deniable than the other.

We’ll see more of this as networks get more complex, nations are more dependent on infrastructure, and resources more scarce. Water is an obvious candidate, since a country which might be diverting water for political reasons can always blame management errors. China and India have already had discussions along these lines, according to Fred Pearce’s book When The Rivers Run Dry.