The G7 summit held in Italy over the weekend concluded with an open rift between the United States and the major European powers. German Chancellor Angela Merkel all but declared that the transatlantic alliance, which provided the basis for post-war stability, is over.

Addressing a Munich beer tent rally on Sunday, Merkel said: “The times when we could fully rely on others are to some extent over—I experienced that in the last few days. We Europeans must really take our destiny into our own hands.”

Merkel was speaking a day after the conclusion of the summit, which saw open conflicts with the US. The rupture took place in the wake of US President Donald Trump’s refusal at a gathering in Brussels to reaffirm a commitment to Article 5 of the NATO treaty, which obligates member states to come to each other’s assistance when attacked. This was followed by a NATO meeting in which he berated the Europeans for “not paying what they should be paying” toward the alliance.

At the G7, the most public conflict centred on an endorsement of the 2015 Paris Agreement on climate change, which the Trump administration considers unjust on the grounds that it restricts economic growth in the US.

The other six members—the UK, France, Italy, Germany, Canada and Japan—refused to back down. As a result, the summit communiqué specifically recorded the objections of the US, stating: “The United States of America is in the process of reviewing its policies on climate change and on the Paris Agreement and thus is not in a position to join the consensus on these topics.”

While there were divergences at previous G7 meetings and varying interpretations offered of decisions reached, the participants were able to paper over their differences in the final communiqué. That did not take place on this occasion.

The conflicts extended into other areas. Before the summit even got underway, the US blocked a move by Italy, the host nation, to have at least some verbal reference to the rights of refugees.

Trade was another contentious issue. The US had secured the removal of references to the need to “resist protectionism” from statements issued by the G20, the finance ministers’ meeting of the G7 and the IMF at gatherings earlier this year.

The G7 communiqué affirmed a commitment to “keep our markets open and to fight protectionism, while standing firm against all unfair trade practices.” However any hopes by European politicians that the inclusion of “fight protectionism” might represent some back down by Washington proved short-lived.

Immediately after the meeting, Trump seized on the reference to “unfair trade practices.” In a series of tweets, he hailed “big results” on trade, highlighting phrases about “the remove of all trade-distorting practices” in order to “foster a truly level playing field,” without mentioning the need to “fight protectionism.”

Earlier in the week, Trump described Germany as “bad, very bad” in a meeting with European officials, according to Spiegel Online. He added: “See the millions of cars they are selling in the US? Terrible. We will stop this.”

Merkel described the talks on the climate agreement as “very unsatisfying,” before going to Munich on Sunday, where she summed up the broader implications of the withdrawal of the UK from the European Union (Brexit) and the clash with the US.

“Of course, we need to have friendly relations with the US and with the UK and with our other neighbours, including Russia,” she said. Even so, she continued, “we have to fight for our own future ourselves.”

The fact that these words were delivered at a Munich beer rally, recalling the start of Adolf Hitler’s political career, added to their significance.

The historic implications of Merkel’s remarks were recognised in a number of comments.

In a Twitter message, US Council on Foreign Relations President Richard Haass said they were a “watershed.” The scenario was “what the US has sought to avoid” since World War II.

Henry Farrell, professor of political science and international affairs at George Washington University, noted in the Washington Post that Merkel’s comments were “an enormous change in political rhetoric.” While the “special relationship” between Britain and the US had assumed more public prominence, “the German-US relationship has arguably been more important.”

One of the purposes of NATO, Farrell wrote, was to “embed Germany in an international framework that would prevent it from becoming a threat to European peace as it had been in World War I and World War II.” He recalled the words of the first NATO secretary-general, Hastings Ismay, that the alliance aimed “to keep the Russians out, the Americans in, and the Germans down.” Now, Germany was seeking to play a more independent role than at any time since the end of World War II.

The immediate cause of the rift at the G7 was almost universally described as Trump’s “boorish” behaviour. But his actions are only the latest, and so far most graphic, expression of the deepening tensions between the major imperialist powers.

At the time of the invasion of Iraq in 2003, Germany opposed military action—motivated by its own economic and strategic interests in the Middle East. In response, Donald Rumsfeld, then US defence secretary, drew a contrast between what he called “old Europe,” the German area of influence, and “new Europe,” the eastern European states more inclined toward the US.

While the transatlantic alliance has been maintained, these divisions have intensified over the past decade, with growing criticism from within German political circles about the disruptive international role of the US and the need for Germany to assert itself on the global arena.

The differences encompass the Middle East, where Germany has considerable economic interests; China, where Germany looks to gain advantage from the One Belt, One Road project of President Xi Jinping; and Russia.

In February 2016, in its statement Socialism and the Fight Against War, the International Committee of the Fourth International called for the development of an international movement of the working class against the danger of a new imperialist world war.

It noted that while American imperialism was the “cockpit of international war planning,” its actions were only the “most concentrated expression of the intractable crisis of capitalism as a world system.”

European and Japanese imperialism, facing the same internal and external contradictions, were pursuing no less predatory aims, the statement explained. “All are attempting to exploit American overreach to secure their stakes into what has degraded into a ferocious battle for the global redivision of world economic and political power.”

As the ruptures at the G7 summit reveal, the divisions between the major powers have widened and the heat of that battle is likely to only intensify.