First world war: principles at stake then still relevant, says Cameron

PM says these include stopping one power from dominating Europe and defending smaller countries from might of bigger ones

Some of the principles at stake in the first world war are still relevant today, such as the need to defend smaller countries from the might of bigger ones, David Cameron has said.

Ahead of commemorations for the centenary of the conflict, the prime minister said it was worth remembering that men rallied to the cause of stopping one big European power "snuffing out" a small country like Belgium.

He told the BBC: "There were important principles at stake – that there shouldn't be the domination of Europe by one power, that small countries had a right to their independence and existence – and these are problems that still confront us today. And some of these problems are actually consequences of the conflicts of the 20th century, of the first world war and the second world war."

The prime minister did not mention any specific conflicts but the centenary falls at a time of violence in Ukraine, Gaza, Libya and Iraq.

On Saturday, Cameron warned of an "arc of instability" stretching through north Africa and the Middle East, and argued that the world was less predictable than ever.

He is due to meet with Nato bosses later on Monday to argue for stronger military presence in eastern Europe in the face of Russian aggression in Crimea and its arming of separatists in Ukraine.

Before that, he gathered in Glasgow with other leaders of the major UK political parties for a commemoration ceremony at Glasgow Cathedral. He next heads to Belgium for an event with other world leaders, while Ed Miliband and Nick Clegg will be at a Westminster Abbey service on Monday evening.

Before the service, the prime minister said remembering "the scale of the slaughter, the way it changed our world" was essential.

"I think it is important to remember the outbreak of the war, because although there was an enormous amount of waste and loss of life, there was a cause that young men rallied to at the beginning of the war, which was the idea that Europe shouldn't be dominated by one power, that a small country like Belgium shouldn't simply be snuffed out. There was a cause that people rallied to, and I think it's worth remembering that, alongside obviously the appalling loss of life and the effect it had on our communities."

Cameron also spoke of one of his relatives who was killed in September 1914 and his intention to visit the battlefield where he died.

"I think lots of the people who joined up thought it would be over quickly, thought the Kaiser would be stopped and everyone would be home and life would go on as before. I think that's one of the reasons we remember the first world war – because it so profoundly changed our world, changed our world in lots of bad ways, but also in some good ways – the emancipation of women, the fact that women then got the vote, participated more in the workforce, there were changes in medicine, massive improvements in our world.

"All those things are worth remembering and that's why as a government and as a country, we should be refurbishing our war memorials, which we are: we should be sending children to go and visit first world war battlefields, we should be studying these things properly in our schools, and we spent a lot of money on the Imperial War Museum in London, which has just reopened and … I thought it was absolutely spellbinding."