At Cabinet level, this is the most united government to rule over Britain for several decades. There is no great schism over an overwhelming policy issue, as there was under John Major. There are no wets and dries debating economic policy to form an echo of the early Thatcher years. There are no Blairites and Brownites disagreeing on the role of the state in the provision of public services, a division that was more ideological than current orthodoxy recognises.
More importantly, the Coalition unites around a common view of what it means to be liberal. Early on in his leadership, David Cameron declared that he was a liberal Tory. Or was it a Tory liberal? The terms became interchangeable and were linked to a policy agenda that chimed increasingly with an influential section of the Liberal Democrats.
In this respect, Cameron's most significant and yet relatively undemanding move since becoming leader was to make overtly clear that he was socially liberal. When he and George Osborne tried to persuade David Laws to defect early in the last parliament, the Lib Dem MP turned them down partly because he feared the Conservative Party was still socially illiberal. That obstacle has gone in the sense that those around Cameron and Osborne are completely and genuinely at ease as social liberals. With social liberalism no longer an issue of any significance, the Coalition takes shape easily around common assumptions about the state, the virtues of localism and the need for a fresh emphasis on civil liberties.
All those commonly held assumptions are being challenged by power. The challenges will not necessarily manifest themselves in splits between the two parties or within them. In some cases, they will be reflected in internal debates within the minds of individual ministers. I have written before about how ministerial disdain for the state and public spending has been tested when individual ministers discover an urgent need for higher investment. As they always knew, their support for localism would be tested by a media culture that dines on stories of splits, whether at a national or local level. But it is in the third area that their view of liberalism was doomed to be tested most intensely.
The balance between civil liberties and security in the era of globalised terror is one that evades the neat precision of most other debates over policy. Charles Clarke was Home Secretary when Tony Blair responded to the terror threat with a populist touch that alienated many Labour-supporting liberals.
Yet Clarke was a liberal-minded politician who thought deeply about what liberalism meant in a transformed international context. No doubt he had private worries about some of Blair's casually authoritarian responses but, when I spoke to him yesterday, Clarke was still firmly in favour of controversial control orders, the measure he introduced to quickly constrain the movement of suspects without the normal judicial process.
"Those who oppose them must either put the case for doing nothing or come up with a workable alternative," he said. "What I don't think is acceptable is a situation where suspects do indeed commit a terrorist act, and we say afterwards that we knew they posed a threat but had no powers to act quickly in order to constrain them. Yet opponents of control orders, orders that are used in a very small number of cases, put forward no workable alternative."
For political leaders the responsibility is great. To some extent, and disgracefully, Blair and Brown played politics with the issue, hoping to expose divisions in the Conservative Party and to win approval in so-called middle England. Ed Miliband was so horrified when Brown attempted to revive attempts to detain suspects without charge that he declined a request to appear on the BBC's Question Time because he could not bring himself to defend the policy.
Even so, crude calculation did not determine policy alone. It is a daunting experience as Prime Minister to receive intelligence reports on potential terrorist attacks. Unlike his former shadow home secretary, David Davis, and senior Liberal Democrats, Cameron is not instinctively liberal in this particular area. Cameron and George Osborne questioned Davis closely and warily in opposition before the duo agreed to oppose some of New Labour's more authoritarian measures. Yet by the time of the Coalition's formation the issue had become less highly charged. There had been no further attack in Britain and senior Labour figures were moving fast to disown their government's at times overwrought onslaught on civil liberty.
Suddenly, the issue becomes highly charged again. If the Coalition negotiations had taken place last weekend, the tone would have been more strained. The more nuanced reflections of Charles Clarke would have featured in some shape or form, even if a potential attack originating from Yemen has no direct connection with issues relating to suspects in the UK. Heightened anxiety is the only link between the two, but it is one that a government cannot ignore.
Nick Clegg was his party's home affairs spokesman before becoming leader. In opposition he worked closely and constructively with David Davis, who declared yesterday that he would vote against the renewal of control orders. I would be very surprised if Clegg has changed his mind on control orders as he has in other policy areas. But, if that is the case, he and Cameron must address Charles Clarke's defining point: if not nothing, then what?
Currently virtually every political figure is a liberal. The term is as fashionable as "progressive". It also invites a thousand different interpretations, from those on the libertarian right to social democrats who regard forms of equality as liberating. The Coalition unites around a fairly precise interpretation but now comes up against a range of imprecise consequences and external challenges. Its support for choice at a local level leads to demands for more grammar schools from some Conservatives, even though such a move would limit the choice for most parents. The support for civil liberties is deep in the case of the Liberal Democrats and more expedient for most Conservative ministers. Both are in a government that faces a shapeless threat that at times seems exaggerated, until terrorists make a tangible move.
The noble innocence of a flexible idea is exposed by the need for pragmatically effective responses to terrorism. Liberalism takes many forms, but no one is liberated if they are blown up.