As expected, Jeremy Corbyn’s has arrived into the leader’s office to find every door he opens booby-trapped. His silence at a memorial service for the Battle of Britain is an act of treason; just as his Shadow Cabinet settles down, his London Mayoral candidate mouths off; stating his long-held position on the EU, he is accused both of u-turning and of failing to compromise. Literally the only thing that seemed capable of breaking the cycle was the story that David Cameron had engaged in oral sex with a dead pig. The most serious traps, however, are not the immediate barking of the press or the faux-outrage of various Labour grandees. During and after party conference, Corbyn must avoid the worst trap of all: the temptation to define himself on a terrain chosen by his enemies.

From the perspective of the Conservative Party and its allies in the press, there should be a simple narrative to exploit: Labour spent too much in government, and now, with Jeremy Corbyn departing from the orthodoxy of austerity and neo-liberalism, their economic credibility is in ruins. Given this easy narrative, and the importance of economic credibility in elections, what is most remarkable about Corbyn’s first couple of weeks is that the Tories and the tabloid press have focussed all of their attacks on other issues: links to Irish republicanism, controversies around the national anthem, rumours that Corbyn wants to “abolish the army”.

The problem for the Tories’ economic credibility narrative is that Corbyn’s departure from the austerity consensus is actually very popular. Cracking down on tax avoidance, establishing a national investment bank and raising taxes on the very rich are all popular policies. Other policies, on social housing and public ownership, are overwhelmingly popular too. As is becoming a theme, the conventional triangulating wisdom points in the opposite direction from the reality. Labour may have tacked left, but it has also just elected a leader who is prepared to stand his ground, defend Labour’s record and offer an alternative.

As the Tories shrink the state to levels similar to that of the US, while probably failing on their own economic terms as well, Corbyn should be on home turf on economic and social policy – and the main tactic of Corbyn’s opponents will be to ensure that this policy never truly gets a hearing. This is a concerted strategy; the first big votes scheduled by the government which are likely to divide the Parliamentary Labour Party will take place over Trident and intervention in Syria.

In effect, the Tories and the tabloid press are drawing the battle away from bread and butter issues and into a kind of modified culture war over the monarchy, the military, and English nationalism. On this terrain, they are hoping to discredit Corbyn on issues where he is likely to represent a minority of the public – to make him look mad and extreme – before he can make an impression by calling for radical but popular social reform. Even if Corbyn wins over a majority of the public on issues like Trident and Syria he will have been forced to spend most of his time talking about issues which have a minimal effect on most people’s everyday lives.

As Labour gathers for its annual conference in Brighton, Trident is being pushed onto the formal agenda – and it would be easy to see it as the defining internal fight of Corbyn’s early leadership. The abolition of Trident is a hugely popular issue among Corbyn’s base, and there will be a temptation among some to prioritise it and the looming vote on Syria as the main focal point for mobilisation. But in reality, what Corbyn needs is the growth of a mass movement against austerity, and a message of hope for people’s lives. Trident may enthuse an activist base, but it is housing, poverty and street-by-street activism that will bring about the movement we need.

For the new Labour leadership, the initial prominence of the Tories’ culture war – monarchy, military, English nationalism – presents a dilemma. The answer is certainly not a miserable compromise: any indication that Corbyn is ceding ground on Trident or foreign policy would be taken as a sign of weakness, and, worse, it would be transparently dishonest. But both the leadership and the activist left should think carefully about where they put their energies for the time being. Offering MPs and free vote on Trident and Syria, while quietly laying the ground for a more authoritative policy position, could be a shrewd move. And when the plethora of activists groups that supported Corbyn begin to formulate their strategies, the focus must be on building movements around workplaces and communities, not just reacting to whatever is happening in parliament.

Corbyn’s election as Labour leader was built on a rising tide anti-establishment sentiment, which has taken root not only in the anti-austerity politics after the economic crash, but also in a generalised mistrust of the media and political elite – a yearning for a new kind of politics. In time, Corbyn, and the nascent movement that he represents, will be able to formulate these projects into a force capable of sweeping away the old constitutional certainties, and challenging the electorate’s attitudes on identity and nationhood. But to start setting the agenda, Corbyn needs to get back onto the front foot. That means moving back onto the terrain of social policy and economics – and quickly.