Leaders are only as strong as the people around them. That may not have been true in bygone ages but it certainly is now.
The pressures from media and politics are so great that even the most single-minded and determined prime minister is going to be weakened within a unified committed team.
I always thought that Thatcher started to wobble when she lost some of the people who had helped bring her to power and advised her in the early years of her administration. She was left with Bernard Ingham (Good and faithful servant though he was, in Robert Harris's words) and Charles Powell. By 1990 they were too close to her.
The same happened with Blair. For various reasons, those who were the focus of the New Labour project began dropping off. Alastair Campbell, for all his faults, was a crucial part of the team and irreplaceable. So was Anji Hunter. Mandelson went off to Europe. The only one of the orginals at the end was the other Powell.
But with Thatcher and Blair, the process of losing the crucial courtiers took years. Cameron is losing his at an alarming rate and he has only been in power for a few months.
As everyone has said, Andy Coulson is a huge loss but only the week before he lost Paul Brown, his grid keeper. Conor Ryan, who knows about these things, believes this will have catastrophic consequences.
The inner circle has already been reduced to little more than Steve Hilton, who has few political instincts. As the hoo-ha over the collapse of the Big Society shows, the Hilton Big Idea is disappearing fast as the cuts bite.
George Osborne has his own agenda which is diametrically opposed to the Cameron/Hilton one. Nick Clegg has a mini agenda of his own.
No one is pulling together (Gove and Lansley off on ego trips of their own). No one is holding things together. Not only are we not all in this together, they aren't even in this together.