I'm sitting in a room in the basement of a building in central London with an Oxford academic who's an expert on war.

So my name is Dr Rob Johnson. My area of research with an Oxford academic who's an expert on war.

So my name's Dr. Rob Johnson.

My area of research is about decision making in crises and in conflicts.

Rob Johnson is showing me a piece of his own family's wartime history.

It's something he always keeps with him.

In front of me, I've got my grandfather's pocket watch,

which he carried during the Battle of Atlantic and the Battle of the Mediterranean at Malta.

And this pocket watch was given to my father and subsequently to me.

Reginald Johnson had been a Shakespearean actor before the Second World War broke out.

Like most of his generation, he put his own dreams on hold to serve the nation in its time of crisis.

His grandson though has dedicated his whole life to defence as a soldier, a scholar and a senior civil servant.

Rob is fiercely loyal to his country and would never want to talk it down, but he's become increasingly worried about the state of the UK's defences

after a prolonged period of peace that's seen the government and society forget what it means to be ready for war.

It's a concern he raised while seconded to the Ministry of Defence.

My job was to try to alert colleagues to what was going on and where the gaps were.

What I found actually was that many, many people agreed with me.

They knew we're in the position we are.

But the response often was, look, government's about choice.

And the government of the day and the governments we've had

have all made the same choice, which is that we're going to invest in

health and education and roads and growth, not in defense.

...