The rest of the Snowden files should be destroyed

So what about the costs and the downsides of the revelations?

There are several items on the list. One is that intelligence capabilities are damaged. There is no doubt that signal intelligence agencies are an essential tool necessary for international statecraft as well as for maintaining the domestic constitutional order. Revealing capabilities and tactics often means they become worthless as a result. Measuring such tactical costs is hard, but the damage is significant.

This means, secondly, that militants, violent extremists, and adversaries—think the Syrian regime—are already racketing up their communication security. In the future it will be harder to detect and foil terrorist attacks. In the future it will be harder to say if some regime possesses or used a specific weapon system. In the future it will be harder to unveil wealth-draining cyberespionage. This is very serious. …

A fourth result: Internet governance is creaking. Diminishing America and Britain’s diplomatic and moral standing is threatening the multistakeholder approach, so far a guarantor for a free and open Internet. A patchwork of smaller, sovereign “Internets” is becoming more and more likely. As a result, the Internet could now become more authoritarian, not less.