Don't listen to Edward Snowden's supporters – his leaks have been a gift to terrorists

Targets have already begun to change the way they communicate, and we're still waiting discover just how bad the consequences will be

Edward Snowden during his interview with NBC’s Brian Williams in Moscow

So this is the house that Edward Snowden built. The introduction of the Freedom Act last week has now reined in the NSA’s powers, particularly regarding the collection of telephony metadata. As part of this, phone records are now in the hands of private companies, rather than the state. This puts the US in the same situation as the UK and, in reality, senior figures in the US intelligence community are relaxed about this, providing the NSA can access them in a speedy manner.

These reforms that have taken place under the Freedom Act are directly attributable to Snowden’s theft of classified documents two years ago and subsequent distribution to journalists. To find out just how high the cost of this has been, I spoke to a range of senior officials in both the US and UK to try and get an idea of the national security impact of Snowden’s disclosures.

Quantifying the damage that has been done is not always easy. If a terror suspect dropped off the radar post-June 2013, it could not always be proved it was because of what he had learned from Snowden; perhaps the timing was a coincidence. Regardless, there are trends emerging.

Firstly, a series of ongoing intelligence operations had to be abandoned. They had been predicated on the pre-June 2013 assumption that they could take place without fear of discovery or attribution. Snowden removed that element of doubt, so the operations were scrapped.

Secondly, there is the knowledge that state adversaries have gone to town on the methodologies that the Snowden files revealed. There is significant fear that China and Russia, for example, have taken stock of Western intelligence agencies’ own cyber strategies and are now going to deploy them back against the US and its allies.

When it comes to stopping terrorist attacks, groups that seek to harm the West also now have an advanced understanding about our capacity to stop them. A video released in January onto a jihadist online platform explained just some of what mujahideen fighters had taken from Snowden: "All mobile phone providers use the same software, your device continuously is in contact with the nearest tower," it says. "Your different coordinates are tracked and stored. All your calls, messages and internet history are stored in this same place […]With his phone, tablet or laptop the enemy can listen/record all conversations and meetings."

The video also provided advice on how to avoid detection, listing software packages that protect against surveillance and where to acquire them from.

Snowden’s disclosures have led to changes in the way that terrorists communicate. One senior US intelligence official told me that, post-Snowden, this was the “most significant change” that had taken place and others have corroborated that this shift has occurred. Speaking in November 2013, then-Chair of the House of Representatives Permanent Select Committee on Intelligence, Mike Rogers, said that Snowden’s disclosures had allowed three different al-Qaeda affiliates to change the way they communicate.

One of the drivers behind this are Snowden’s disclosures regarding Section 702, which governs the interception of communications of foreign nationals based outside the US, in order to acquire foreign intelligence relating to national security, foreign affairs and national defence. Snowden allowed terrorists to wise up to the fact that even if you are sitting in Yemen and emailing Somalia, your communications will still often pass through the US. He also allowed them to figure out which companies were complying with the US government in giving access to this data. Terrorist groups quickly switched communication service providers or dropped off the electronic radar altogether.

Snowden’s actions have also led to terrorist groups developing new encryption technology. Experts at GCHQ talk of how cracking the communications of a high value national security target can take three times as long as it once did. That can mean the difference between life and death. Yet it’s not just terrorists who Snowden has strengthened. In Britain, GCHQ’s ability to monitor crime gangs – including those involved in people trafficking and drugs – has been reduced by a quarter.

To Snowden’s supporters, such things are usually irrelevant. But for everybody else, what should concern us is that the damage we know Snowden caused so far could actually just be scratching the surface. As Sir John Sawers, the former head of MI6, said earlier this year, “Snowden threw a massive rock in the pool and the ripples haven't stopped yet.”

These ripples occur at a time the threat to the West from a variety of state and non-state actors grows. While we may be getting an idea of the damage Snowden caused in the past, there is still ample reason to fear what more he could cause in the future.

Robin Simcox is the national security fellow at the Henry Jackson Society, a foreign policy think tank in London.