Talking of leaders having to grow into their roles...

At this morning’s press conference there was a moment when David Cameron didn’t quite look as comfortable in front of the cameras as he usually does.

The whole session had been delayed by 45 minutes while the PM was briefed on the tragic death of Linda Norgrove and the rescue operation that preceded it.

So his discomfort may have simply been the shock of discovering that the aid worker could actually have been killed by American troops.

But it may also have been the weight of having to face the press, while tip-toeing through the political minefield of calling for a tough investigation into the incident, while not being seen to criticise the American military.

I thought he was a little wrong footed by questions on his decision to approve the operation – in particular one on whether British special forces should have carried out the operation instead of the Americans who, insinuated one questioning hack, are considered more trigger happy.

While spending cuts have presented a challenge to the new PM, he has looked capable at dealing with the fall-out. That is in large part because he’s been able to dictate the story.

But today Cameron discovered the terrible side of what it’s like to be in power – unexpected events require big decisions, which although taken in earnest, can lead to terrible consequences.