Prime Minister David Cameron has told Scots that the Union makes them safer in a “dangerous and insecure world”.
Asked about the independence referendum while at the Nato summit in Wales, the Conservative leader said the military conference was “a time when you reflect on the dangers of our world”.
He claimed that security was “one of the strongest arguments” for voting No on September 18, and cast doubt on Scotland being re-admitted to Nato if the verdict was Yes.
Mr Cameron said: “I think there is total confusion about whether a separated Scotland would have a place in the European Union or in Nato, or what currency it would use and all the rest of it.
“In terms of the last two weeks of this campaign, what I will be wanting to stress is just what a vital and important question this is.”
He added: “Obviously, at a Nato conference it’s a time when you reflect on the dangers in our world and I don’t think anybody can be in any doubt that we live in a very dangerous and insecure world.
“I would have thought one of the strongest arguments that those of us that want to see the United Kingdom stay together can make is: in that dangerous and insecure world with terrorist threats and other threats, isn’t it better to be part of a United Kingdom that has a top five defence budget and some of the best security and intelligence services anywhere in the world?
“That is part of every single alliance that really matters in the world, in terms of Nato, the G8, the G20, the European Union, a permanent member of the security council of UN.
“To have all those networks and abilities to work with allies to keep us safe, isn’t it better to have those things than to separate yourself from them?”