Earlier this month the Pentagon decided not to send a second aircraft carrier battle group to the Arabian Gulf. The US has maintained two carriers in the Gulf for most of the last two years.

The carriers are there in part to pressure Iran over its nuclear weapons programme. Stopping that programme is a central objective of US foreign policy.

Why has the US suddenly decided to undermine its own military option over the Iranian bomb?

The answer has nothing to do with the Iranians and everything to do with the Tea Party.

The new generation of conservatives in the US, the UK and elsewhere has introduced a new politics of defence. The uniformed military will need to reorient its political radar, while unexpected opportunities loom for the Democrats and Labour.

The Pentagon did not send the carrier because of the upcoming "sequester" of the US federal budget. Over the next six months, the US Navy is likely to see $4 billion stripped from its accounts.

The sequester was a kind of mutual suicide pact agreed between Obama and the Congress in 2011. If agreement could not be reached on deficit reduction, huge automatic budget cuts would kick in from March 1, 2013 hitting mainly the military and discretionary domestic spending.

The idea was that the Democrats would be motivated to avoid cuts to precious domestic programmes, while Republicans would be desperate to avoid defence cuts.

On this last point, everyone was wrong.

As the website of the Tea Party Patriots announces, "Even Defense Spending Can Be Cut".

Tough talk



Among the new model conservatives, the "budget hawks" have eaten the "chicken hawks".

Wealthy Republicans usually have had more important things to do than serve in their nations' armed forces. Yet, under George W Bush, these chicken hawks were outspoken advocates of placing their fellow citizens in uniform in harm's way in Afghanistan and Iraq.

Sequestration will damage US social safety net

Today, the commitment to austerity politics trumps national security. The idea that budget deficits and "big government" are the gravest threat to the economy defines David Cameron's Tories just as it does the Tea Party.

Of course, the new conservatives often still talk tough on security. But they are only willing to use deficit spending to fund tax cuts for the wealthy, not for defence.

Ever since Libya, Cameron has enjoyed his time as La Petite Napoleon, blissfully unaware he is running his country's armed forces into the ground. His government has inflicted savage cuts on defence to the tune of 17 percent over the period 2011-2015.

Similarly, the Tea Party says it wants to increase the size of the US Navy and the Air Force. But their refusal to contemplate tax increases will lead to $43 billion in cuts (nearly 8 percent) for the Pentagon for the remaining six months of fiscal year 2013 alone.

Many Tea Partiers were shocked by the lying, venality and corruption that accompanied GW Bush's adventures in Iraq and Afghanistan. Some even worked with the radical left group Code Pink to oppose the wars. In response, they have developed a kind of neo-isolationist national security policy. Putatively, this is based on a strong military coupled with no foreign entanglements or messy, neo-imperialist wars.

As admirals with empty coffers can attest, however, the problem is that in practice the Tea Party is not prepared to fund the strong defence part of the equation.

Defence spending



This shift in the politics of defence is nothing short of spectacular. In the US and the UK, high defence budgets have been a rare point of relative agreement among elected politicians. The reasons are not hard to divine: pork barrel spending for an industry wrapped in a flag.

As Winston Churchill remarked of peacetime deliberations over how many battleships to buy: "In the end a curious and characteristic solution was reached. The Admiralty had demanded six ships: the economists offered four: and we finally compromised on eight."

Such "military Keynesianism" was a reliable feature of the Cold War. 9/11 headed off talk in the 1990s of the "peace dividend" and gave military largess another decade to run.

But now conservatives are committed to starving their economies of government spending as priority number one. Despite leading a recovering economy into a double and potentially triple dip recession, politicians like Britain's Chancellor of the Exchequer George Osborne remain committed to austerity politics come hell or high water.

The question becomes what are the politics of this new realignment in defence? What challenges and opportunities are in store for the military and for the centre-left parties in the US and the UK?

By their nature, military officers are predisposed to conservative politics. Yet, they believe passionately in the value of public service and sacrifice. With their own eyes they have seen "big government" work wonders in defence of the common good. They have seen young men and women from the wrong side of the tracks saved from wasted lives by the values military service instils. In the US, they know that multi-cultural, racially integrated institutions can function smoothly and effectively. In both countries, many also have respect for - and a level of comfort with - their gay and lesbian colleagues.

Contempt for military service



Such officers have little in common with today's conservatives, very few of whom have ever worn a uniform. In turn, the conservatives have little appreciation for the military or knowledge of its ways or needs.

Cameron's Tories, for example, cut the overworked British Army by 20,000 in the midst of the war in Afghanistan. They papered over the cuts with an ill-considered policy of relying on reserves. Into these wounds they rubbed salt mixed with contempt by appointing the ageing playboy Duke of Westminster as commander of the reserves, although he has now resigned.

A well-known frequenter of prostitutes, the fabulously wealthy Duke allegedly made use of the same escort agency as disgraced former New York Governor Eliot Spitzer. Reasonably spry, he managed to go through four high end prostitutes in one six week stretch. In an unconscionable breach of personal and national security, he apparently told prostitutes who he was, an act that would have seen officers who served under him stripped of their security clearances and their careers.

Similar, if somewhat less raunchy, contempt for military service has been demonstrated by Republicans in the US. Despite his two Purple Hearts and service as a squad leader in Vietnam, Chuck Hagel was given no respect by his former Republican colleagues during his confirmation hearings. Or consider Joe Walsh, a Tea Party candidate for the House in Illinois in 2012. He ran against Iraq veteran Tammy Duckworth, who lost both her legs in combat piloting a helicopter. Walsh accused Duckworth of being more interested in choosing dresses than in debating him. Duckworth replied that for most of her adult life she had worn one colour only: camouflage.

Duckworth is a Democrat, and in that fact lays the point of these stories. If they can overcome their own prejudices about the military, the Democrats and Labour have an historic opportunity to realign the politics of defence in their favour.

Military values of collective effort and shared sacrifice, and of honouring public service, have much in common with centre-left parties trying to halt the privatisation of state and society by conservatives.

As of May 2012, there were already 1.6 million discharged veterans of Iraq and Afghanistan in the US. That's a lot of votes from people who will rely on the Veterans Administration for medical care, who will receive government pensions, and who will go to university on their GI Bills. All they ask is a fair deal from the society they risked life and limb for.

Such veterans have worked hard and are self-reliant. But they also have a legitimate need for public benefits. They could be at the heart of - and a symbol for - a new coalition for the recovery of the ideal of the common good and of the state as the rightful advocate of those in need.

The Republicans and the Tories have made a potentially fatal error. In abandoning the politics of national security, they risk appearing as exactly what they are: parties of rich white men who want to get richer at everyone else's expense.

But do the Democrats and Labour have the vision to pick up the sword the conservatives have left lying on the floor?

Tarak Barkawi is Associate Professor in the Department of Politics, New School for Social Research.