Before Hilary Benn sat down from his contribution to the Syria debate in the House of Commons last night, the political echo chamber was reverberating. Over the applause, microphones picked up outbursts of praise from the Conservative benches that were echoed through the commentariat: ‘superb’, ‘historic’, ‘career-defining’. It was certainly an impressive feat of rhetoric, all the more so for having been written largely during the debate. But at the core of the rhetoric were two distortions, which aped the language of socialist internationalism while arguing for its opposite.

Urging the Commons to confront a new kind of ‘fascism’, Benn invoked the legacy of the International Brigades who went to fight Franco in Spain in the late 1930s. Just as those brave socialists and trade unionists volunteered to fight fascism in Europe, he implied, so we must fight Daesh now.

Nothing could be further from the spirit of the International Brigades than Cameron’s bombing campaign in Syria. The International Brigades were criminalised by the British government, which rehabilitated the 1870 Foreign Enlistment Act, and when they arrived they found themselves fighting a losing ground war, mile-by-mile across Spain. On Wednesday night, MPs voted for a bombing campaign from the air, undertaken by the British state in alliance with the largest military superpower in the world. It is more a gesture than a strategy, though no less deadly for the civilian population of Raqqa.

The International Brigades fought the rise of a dictator. But Cameron’s bombing campaign is not targeted at Assad, who is responsible for far more civilian deaths and whose ideology is much closer to fascism than Daesh’s violent religious fundamentalism is. In practice, British warplanes are cementing Assad’s position, and while Western governments have all said they want him to go eventually, they have form in the Middle East, from supporting Saddam Hussein before 1990 to their alliance with Saudi Arabia now.

There are brave young volunteers going to Syria to fight against both Daesh and Assad, but like their predecessors in the 1930s they are criminalised by the British state. Less than a month ago, a British court sentenced an 18 year-old woman to 21 months in prison under the Terrorism Act 2006. She had volunteered to fight for the Kurdistan Workers’ Party (PKK), which is listed as a terrorist organisation in Britain at Turkey’s behest. Turkey, the only Nato member in the region, is bombing the Kurds and is complicit in funding ISIL. Hilary Benn backed the Terrorism Act 2006.

Perhaps the most startling element of Hilary Benn’s speech was his appeal to the Labour Party’s ‘internationalism’. On Tuesday, the Shadow Defence Secretary Maria Eagle wrote in the Mirror that ‘Labour are a proudly internationalist party’ and that therefore it had a duty to back the bombing mission.

Socialist internationalism is rooted in the principle that the left needs its own axis of international solidarity. There are many criticisms you can make of the brutal, opportunistic policies of the big world powers, but a lack of international perspective is not one of them. And big business is internationalist too: its demand for markets, raw materials and labour to exploit does not stop at borders. Internationalism is about more than ‘not walking by on the other side of the street’, as Benn put it – it is supposed to be labour’s answer to capital’s global power.

Benn and Eagle’s understanding of internationalism betrays a deeply institutionalised understanding of Labour’s purpose. When Jeremy Corbyn and others on the Labour left oppose war, it is not just because they deem the case weak and the civilian casualties unjustified – it is also because they understand that ‘we’ will not be bombing Syria at all: the British state will be. For Benn, as for most other front bench Labour politicians over the past century, the Labour Party is part of the sensible establishment that runs the state. It is only under this assumption that it makes sense not only to maintain a nuclear deterrent and an interventionist foreign policy, but to establish it as a funding priority above schools and hospitals, even when the public oppose it.

None of this is to say that Benn, Eagle or Alan Johnson are Tories in disguise. But the battle for Labour’s foreign policy reveals a sharp ideological difference between a brand of establishment social democracy and a renewed political force to its left. In his speech supporting military action in Syria on Wednesday, Benn colonised language that rightly belongs to his radical political rivals, and, in distorting it, made it meaningless.