"Germany's security is being defended in the Hindu Kush, too," said Peter Struck, who was Germany's defence minister at the time, in 2002. If that's true, then the government should also be expected to defend the security of its people at their own doorstep. Because the massive sniffing out and saving of data of all kinds – that of citizens and businesses, newspapers, political parties, government agencies – is in the end just that: a question of security. It is about the principles of the rule of law. And it is a matter of national security.

We live in changing times. At the beginning of last week, we thought after the announcement of the American Prism programme that President Barack Obama was the sole boss of the largest and most extensive control system in human history. That was an error.

Since Friday, we have known that the British intelligence agency GCHQ is "worse than the United States". Those are the words of Edward Snowden, the IT expert who uncovered the most serious surveillance scandal of all time. American and British intelligence agencies are monitoring all communication data. And what does our chancellor do? She says: "The internet is uncharted territory for us all."

That's not enough. In the coming weeks, the German government needs to show that it is bound to its citizens and not to an intelligence-industrial complex that abuses our entire lives as some kind of data mine. The justice minister, Sabine Leutheusser-Schnarrenberger, hit the right note when she said she was shocked by this "Hollywood-style nightmare".

We have Snowden to thank for this insight into the interaction of an uncanny club, the Alliance of Five Eyes. Since the second world war, the five Anglo-Saxon countries of Great Britain, the United States, Australia, New Zealand and Canada have maintained close intelligence co-operation, which apparently has got completely out of control.

It may be up to the Americans and the British to decide how they handle questions of freedom and the protection of their citizens from government intrusion. But they have no right to subject the citizens of other countries to their control. The shoulder-shrugging explanation by Washington and London that they have operated within the law is absurd. They are not our laws. We didn't make them. We shouldn't be subject to them.

The totalitarianism of the security mindset protects itself with a sentence: if you have nothing to hide, you have nothing to fear. But first, that contains a presumption: we have not asked the NSA and GCHQ to "protect" us. And second, the sentence is a stupid one: because we all have something to hide, whether it pertains to our private lives or to our business secrets.

Thus the data scandal doesn't pertain just to our legal principles, but to our security as well. We were lucky that Snowden, who revealed the spying to the entire world, is not a criminal, but an idealist. He wanted to warn the world, not blackmail it. But he could have used his information for criminal purposes, as well. His case proves that no agency in the world can guarantee the security of the data it collects – which is why no agency should collect data in such abundance in the first place.

That is the well-known paradox of totalitarian security policy. Our security is jeopardised by the very actions that are supposed to protect it.

So what should happen now? European institutions must take control of the data infrastructure and ensure its protection. The freedom of data traffic is just as important as the European freedom of exchange in goods, services and money. But above all, the practices of the Americans and British must come to an end. Immediately.

It is the responsibility of the German government to see to it that the programmes of the NSA and GCHQ no longer process the data of German citizens and companies without giving them the opportunity for legal defence. A government that cannot make that assurance is failing in one of its fundamental obligations: to protect its own citizens from the grasp of foreign powers.

Germans should closely observe how Angela Merkel now behaves. And if the opposition Social Democrats and Green party are still looking for a campaign issue, they need look no further.

• This article originally appeared on Spiegel International and is republished with permission