John Le Carré’s fictional spymaster George Smiley once said that each of us only has “a quantum of compassion”, which we must use sparingly or lose entirely. Most MPs have more than that, but they do tend to have only a quantum of interest: one or two areas of public policy on which they have strongly held and well-informed opinions, usually but not exclusively related to their careers before they arrived at Westminster.

The parliamentary Labour Party is well-served for experts on various spheres of domestic policy but eyes glaze over when conversation drifts to foreign affairs. Jeremy Corbyn is a rare exception; his area of expertise and his most strongly held convictions relate to the rest of the world. (Despite being an instinctive Eurosceptic, the Labour leader, as with most of his colleagues, doesn’t really regard the European Union as “properly abroad”.) In domestic matters, he tends to defer to his close allies, John McDonnell and Diane Abbott.

That makes foreign policy a lucrative topic on which to attack Corbyn, at least in theory. Much to the frustration of some of his aides, this is one arena in which the Labour leader cannot be persuaded to duck a fight.

The crisis in Venezuela is a case in point. The Conservatives want to weaponise the economic and political chaos to paint a lurid picture about what life under a Corbyn government would look like. Although most MPs from the party’s Corbynite wing have praised Nicolás Maduro’s government in the past, their attachment to the nation is weak. For the most part, they would happily throw out a strongly worded statement in order to bring the row to a close. But Corbyn doesn’t want to and refuses to abandon his principles.

Conservatives have a point, in that Corbyn’s support for the Venezuelan government goes beyond his usual support for the underdog. The oil-rich state was, for a little while, held up in some sections of the left as proof-of-concept that another way of running the economy was possible. That emotional attachment led to an equivocal statement in which the Labour leader condemned “violence on both sides”, which amounted to a de facto endorsement of the government. That makes it easier for the Tories to press the point that today’s Venezuela is what Corbyn’s Britain would one day look like.

Downing Street does badly need to find something to say about why a Corbyn government would be worse than restoring the Tory parliamentary majority at the next election, whenever that may be. Our economy is making worrying sounds – consumer spending fell for the third successive month in July, usually the prelude to a downturn at best and a full-blown recession at worst. That would threaten the Conservative lead on economic competence, which acted as a shock absorber even as Theresa May’s popularity collapsed and Labour surged at the last election. If the next vote happened against a backdrop of economic turmoil, the Conservatives believe they could at least argue that Corbyn’s socialist vision, like Venezuela, is doomed to fail. Things have never been worse, don’t let Labour ruin it.

The same line worked for David Cameron, after a fashion. There is an irony that a Conservative leadership that, for a time, gleefully defined itself by ripping up the Cameroon playbook now runs to it in a desperate attempt to revive the party’s fortunes. Theresa May has even taken a leaf out of Cameron’s approach to hiring spin doctors, luring Robbie Gibb from his post as director of political programming at the BBC to oversee communications at No 10, just as Cameron poached Craig Oliver, his press chief at the time of his 2015 victory, from the BBC.

Gibb’s hiring also served as a statement of intent. If May can still hire from the top shelf as far as experienced professionals go, it sends a message that, at least as far as she is concerned, there is still some life left in her administration. Whether through coincidence or brilliance, the Tory attack machine has sparked into something resembling life since Gibb arrived at Downing Street. (The hiring of Carrie Symonds, a former special adviser to Sajid Javid and John Whittingdale, in the same role at Conservative Campaign Headquarters is also credited for the revival in some circles.)

For the first time since May took up residence in Downing Street, the Conservative Party is driving the headlines and dominating the agenda, as far as chatter at Westminster (and on sunbeds around the world) goes. Tory MPs have lines to take and messages to retweet. Labour veterans note that, once again, attacks on their party are finding their way to Guido Fawkes, a right-wing website that specialises in political gossip (with a particular focus on left-bashing). Their suspicion is that the old Cameron-era arrangement, where the fruits of CCHQ’s research made their way to friendly journalists, is back and working again.

All of this has been enough for a growing mood of optimism to flourish in the Conservative ranks. Whatever might happen with the British economy or the Brexit talks, many now think that the party can stay in power after the next election with an essentially unchanged approach, provided that they find the right replacement for Theresa May.

The good news for Labour is that most of the public doesn’t have a flicker, let alone a quantum, of interest in foreign affairs. They have considerably more than a quantum of interest in whether or not they are still in work, if they can keep a roof over their heads and in what state Brexit leaves the United Kingdom.

It is on these issues that the Conservative Party still has precious little to say. The Conservatives might be able to win an argument about Venezuela but it doesn’t get them any closer to winning an election.