With geopolitical tensions mounting, this is hardly a surprise. But internally, there is a substantial threat, too: the European Commission is less and less inclined to discipline EU member states when they violate European laws and regulations.

As the guardian of the European treaties, the commission must act to ensure that all member states, large and small, comply with European rules that they themselves have drawn up. As an independent watchdog, the commission can launch infringement procedures and take member states to the European Court of Justice if they do not comply.

But now, all too often the watchdog just barks a little before returning to its kennel. Since 2004, the number of infringement procedures launched by the commission has "plummeted to lows not witnessed since the early 1980s", Daniel Kelemen of the State University of New Jersey and Tommaso Pavone of the University of Arizona write in their recent study Where Have the Guardians Gone?.

As a result, member states increasingly become their own referee.

They have never been keen to punish each other. And now, in order to get away with violations themselves, they increasingly allow others to do the same.

Unfortunately, when this kind of horse trading starts, power becomes a factor and large countries have a stronger hand than small ones. This is dangerous: one of the key functions of European integration after two world wars was, and still is, to keep large member states in check so they do not overpower and trample the smaller ones ever again.

Recent examples abound of the commission's increasing reluctance to launch infringement procedures. It refused to act against the Irish Data Protection Commission for failing to uphold Europeans' privacy rights.

The commission brushed Germany's Dieselgate under the carpet. It lets member states violate Schengen rules and carry out illegal pushbacks of migrants and refugees.

And when it comes to severe rule of law violations in Poland, Hungary, Romania or elsewhere, it is extremely reticent to use its powers.

During a European Council meeting in Brussels in October, Germany, France and Italy agreed that the problem of the rule of law is political, and that "political problems can't always be solved in court". If this sets the trend for 2022, we will see even more dialogue and negotiation than last year.

Why has the commission refrained from aggressive enforcement since the mid-2000s? Kelemen and Pavone offer an interesting explanation: the commission feared "this would jeopardise intergovernmental support for its policy proposals".

By embracing dialogue with governments over robust enforcement, it sacrificed its role as a guardian of the treaties to safeguard its other role, namely as an engine of integration.

So, the cause of this new policy of 'forbearance' was not so much direct pressure from member states on the commission, but a deliberate decision by the commission itself to be more tolerant and forthcoming. The report contains long interviews with anonymous commission officials, MEPs and other insiders offering insight into the origins of this policy of tolerance.

Began with Barroso

It began under commission president José Manuel Barroso. When he took office in 2004, the decision to start an infringement procedure against a member state was almost a technical decision.

Often, it was initiated at a lower level in the commission, without Barroso even being aware of it. Member states were often surprised by infringement procedures, too. Since there was no 'system', they hardly ever saw them coming.

At European Council meetings some heads of state and government, embarrassed by a new procedure against their country, would lash out against Barroso. Again and again, the commission president found himself at a loss for words because he did not know what they were talking about.

In 2005, in referendums, the French and Dutch said 'no' to the European Constitution.

This greatly worried Barroso: were some of the founding member states turning against European integration and the Commission's agenda-setting role? As a former prime minister, he wanted to reassure member states, not antagonise them.

He set up a system with a database, streamlining and centralising internal decision-making about infringement procedures. This enabled both him and member states to keep an eye on these procedures.

As a result, Mr Barroso often reined in bureaucrats – sometimes called 'ayatollahs' - who handled infringements, hoping a more relaxed enforcement approach would win plaudits from national capitals.

Since then, some infringements are prevented altogether, because member states become aware of their violations at an earlier stage and correct their behaviour in time. Some cases are now settled by arbitration, which previously was not possible.

But others were quietly dropped under Barroso, including two cases against Germany – one about 'golden shares' at Volkswagen, another about a bottle deposit scheme which then-chancellor Gerhard Schröder was very upset about.

This way, by being less antagonistic towards governments, Barroso tried to counter the often-heard reproach that the commission was not democratically elected and therefore illegitimate.

His successors, Jean-Claude Juncker and Ursula Von der Leyen, more or less continued the strategy.

In times of crisis, when heads of government take difficult European decisions that deeply affect national politics and which they therefore have to legitimise at home, it is understandable that the commission is reluctant to punish member states unnecessarily and indiscriminately.

Without ownership by member states and citizens, the European Union will not get very far.

However, what the Commission may have gained in democratic legitimacy, it lost in authority as a guardian of the treaties. The European Parliament recently took the Commission to court for negligence: its failure to suspend payments to member states violating the rule of law.

This should be seen as a warning shot: the EU should not become an intergovernmental free-for-all, least of all when it comes to fundamental matters such as the rule of law or fundamental rights.

Without an independent guardian of the treaties, Europe will lose its moral compass.