In politics, luck is crucial. It might seem surprising to cite Margaret Thatcher’s career as evidence for that proposition: not so. In retrospect, she can easily seem to have been invincible, at home and abroad. But suppose Jim Callaghan had called an election in October 1978? Assume that Denis Healey had defeated Michael Foot in the Labour leadership contest, Galtieri had accepted the Peruvian peace proposals, or Scargill had agreed to the Nacods terms. History could have been very different. Foot, Galtieri, Scargill, Kinnock: throughout most of her career, Mrs Thatcher was always lucky in her opponents – until the final phase, when she came up against Geoffrey Howe and Michael Heseltine.

To be fair to the old girl, she always exploited her luck. Her foes must have felt that they were dealing with Don Bradman. Drop a catch off him when he had barely got going and a great groan would reverberate among all the non-Australians. They would know that there would be no next chance until at least tea-time tomorrow.

Although Theresa May does not resemble Margaret Thatcher or Don Bradman, she too has been lucky. Last new year, it was inconceivable that she would end the year as Prime Minister. But David Cameron imploded. So did all her possible rivals. The ball did break loose from the scrum; Mrs May seized her chance. It also seemed that she she was putting the accidents of the succession process behind her. She had presence. She seemed authoritative. She looked and sounded like a Prime Minister. Then the problems began.

To be fair to the new PM, she inherited an exceedingly difficult wicket. But she wanted the job; she has to make the best of it. There have been some wrong decisions and – even worse – a failure to take vital decisions. In hindsight, it seems inconceivable that anyone would have thought it possible to fire the trigger on Article 50 without Parliamentary debates and votes. If those had taken place, everything would have been sorted out before the end of November. As it is, the Government has been made to look foolish. If there were a semi-competent Leader of the Opposition, that would be even more apparent. But poor hapless old Corbyn has all the force of a weak school master trying to draw attention to his plight by knocking on the door of the stationery cupboard, in which the lower fourth have locked him, in the hope that someone will let him out. Such a cupboard might also contain politics text books. In their future editions, Mr Corbyn’s name is bound to appear – making the argument that the British system needs a strong opposition. Even so, if governments lose their authority, things go wrong.

Authority requires decisiveness: to govern is to choose. For some weeks now, Mrs May has been confronted by two choices, and the answers ought to be self-evident. The first is Britain’s membership of the Single Market. If Brexit means anything, we have to leave. The second is the customs union: ditto. If we asked to stay in the Single Market and the customs union, we would have many of the disadvantages of EU membership with fewer benefits. It makes sense for remainers, overt or covert, to press for the Single Market, as a means of undermining Brexit. Otherwise, it is absurd.

For weeks now, the PM has been pressed to take a decision. None has been forthcoming.

There is an irony in all this. Many Tories, and not just Euro-fanatics, were uneasy at the prospect of David Davis in a senior position. Those fears have proved wholly unjustified. Decisive, collegiate, the master of his brief, he has been at least as successful as any member of the new Cabinet. But he can only do so much. His boss has got to assert herself. Otherwise, everything is condemned to drift, which the country cannot afford.

Drift, and unhappiness. Although Mrs May is not necessarily to blame for the Ivan Rogers degringolade, it is worth noting that nothing like this ever happened in Margaret Thatcher’s years. Strong herself, she found no difficulty in retaining the loyalty of strong and able officials (on occasions, ministers were another matter). It would be foolish to read too much into one resignation, except for the rumours. There are a lot of reports that ministers and officials are increasingly unhappy with No.10’s way of doing things. Suspicion always seems to prevail over inclusiveness; I have heard the word paranoia used by more than one person.

The two chiefs of staff, Fiona Hill and Nicholas Timothy, are coming in for especial criticism. There are allegations of rudeness and arrogance. If these are true, it is a bad business. No spad, however senior, should behave in such a fashion. Life in No.10 is bound to be difficult enough, without gratuitous Gordon Brown-style increases in the stress level. Moreover, most of those who have come in contact with Miss Hill are unimpressed by her mental powers and regard her as a blatant case of over-promotion. Although Mr Timothy does have a brain, he has clearly come to the conclusion that he is one of the major political intellects of our time. That does not command widespread agreement. To be fair, they have both demonstrated considerable powers – of nuisance value. Beyond that, their role is less clear while their forays into diplomacy are damaging.

Last week, it was revealed that they had fixed up a meeting between Mrs May and Mr Trump. That might sound like a good idea, but only to those who do not understand diplomacy. We have an Ambassador in Washington and a very good one. Kim Darroch is experienced, shrewd, sardonic, wise and able: the perfect man for the tricky task of negotiating the relationship with the new Administration. Freelance spaddery is no help at all. The risk is that it could undermine the Ambassador’s standing. When he deals with the State Department or the White House, it has to be absolutely clear that he is speaking for HMG. By going to Washington, Miss Hill and Mr Timothy gratified their own vanity. They did not help British foreign policy.

Instead – if they are up to it – they should be helping their boss to assert her authority, by explaining who she is and what she believes: by expounding her equivalent of de Gaulle’s certain idea of France. As matters stand, no-one seems to know what moves her to her political soul, or what took her into politics. She appears to lack both breadth of vision and generosity of spirit. If Margaret Thatcher had found herself taking Britain out of the EU, she would have started by summoning a broad canvass for a big picture. Everyone would know where she stood, where they stood, what Britain was doing.

In her speech on Monday about the “shared society”, it was assumed that the the PM would try to fill some of the gaps. But there was more obfuscation than clarity. The shared society is obviously a successor to David Cameron’s big society. To be fair to Mrs May, David Cameron never made it clear what the big society meant, but he did project it with a force of personality which she appears to lack. Both of them seem to agree that a lot of people are feeling economically insecure: hardly an original insight. They both believe that the power of the state should be used to promote social improvement: ditto. Beyond that, where might we be going – and what happened to those traditional Tory cries, freedom and opportunity? Even when they are discussing problems, Tories ought to encourage people to feel good about themselves and their country: to excite animal spirits, as Ronald Reagan did. Thus far, Theresa May is more like Jimmy Carter

At moments, indeed, Mrs May came perilously close to sounding Corbynesque. She enjoys deploring privilege, but before she next uses that word, she should ponder its Latin root. It means private law, but there are no private laws in Britain. It is true that people who have done well for themselves usually spend their money to ensure that their children have a good education. Who can blame them? Certainly not a grammar-school girl. Rather than attack privilege and sounding like an egalitarian socialist, Mrs May ought to commit herself to the eradication of bad schools, whose continued existence is a disgrace. Tories ought to embrace social generosity, but that does not mean sniping at those who do well. It simply means striving to the uttermost to give everyone the chance to do well. That is an inspiring theme, and Theresa May could do with some inspiration – as an alternative to authoritarian dithering.

That damaging message is getting across. Tory remainers are beginning to pick themselves up and dust themselves down. Is it inevitable that we will leave? In response, some Brexiters are becoming nervous and reminding themselves that she was not one of them. Can they trust her? She cannot just rely on Mr Corbyn. Clarity and grip are called for, urgently. A clergyman’s daughter ought not to need reminding of the dangers if the trumpet give forth an uncertain sound.