Anglo-French Troops Train In Defence Alliance

British and French troops are training together in Northumberland this week as the two countries adopt the closest military alliance in their joint history.

Soldiers from Britain's 5 Scots are alongside a French Army Parachute Company from the French 11th Parachute Brigade for the live fire exercise in Otterburn.

The Ministry of Defence said: "Exercise Boars Head is part of the continuing relationship between French and British Army units following the signing of the Defence and Security Co-operation Treaty. It is a natural, and logical, step in our relationship."

French President Nicolas Sarkozy and British Prime Minister David Cameron signed two historic defence and security treaties in November 2010 at Lancaster House in London.

The treaties, which are designed to last 50 years, represent an unprecedented level of co-operation between the two countries.

One treaty will see military co-operation with options including the sharing of aircraft carriers and the deployment of ground troops from both countries under a single British or French commander.

Industrial co-operation will be enhanced too, with agreement on a 10-year plan to ensure that the two countries' defence industries are enhancing each other's work rather than duplicating it.

The other separate treaty allows for greater nuclear co-operation. France and Britain are the only two states with nuclear weapons in Europe.

The two leaders announced what amount to unprecedented levels of knowledge-sharing on nuclear capabilities.

The exercise in Northumberland involves a wide range of live firing exercises. A range of supporting weapon systems from both countries will be used.

The French troops will conduct live fire attacks supported by a British Fire Support team.

The troops will be watched by two top generals from the two armies: the UK Commander of Land Forces, General Sir Nick Parker and his French counterpart, Lt Gen Herve Charpentier, Commander Forces de Terrestres.

The two countries have worked alongside each other before in Bosnia, in the Congo and to a smaller extent in Afghanistan.

The aim now is to create a bi-national Rapid Reaction Force - two units of 5,000 or so troops under one French or British commander.

It could deploy anywhere at short notice, operating either bilaterally or through Nato.

Operating together allows the UK and French governments to implement significant savings in their defence budgets while maintaining similar levels of operational ability - albeit shared.

British military sources say it is an obvious alliance. Britain and France are the only two European countries with a seat at the UN Security Council.

They are the two biggest spenders on defence in Europe, they face similar threats and they have common interests.

But some analysts are sceptical of the plan, which they say will only work while the politicians agree and while Anglo-French foreign policy remains broadly the same.

A senior source within the French defence sector told Sky News that implementation of the new treaties is broadly going very well but it would take time for it to work properly. He said: "Naval and Air Force co-operation is very good, but has always been.

"Between the Army things have always been more difficult. They began to know each other in Kosovo and now in Afghanistan but nothing to be compared with Navy and Air Force."

He added: "It will take time for the man in MoD Whitehall to call his chum in the French Ministry of Defence as he does with his friend in the Department of Defence in Washington."

Historically, France and the UK have not been close.

Militarily, the UK has tended to lean away from France and the rest of Europe and position itself alongside the United States. France on the other hand has carved itself an independent path, often contrary to US policy.

The 2003 Iraq war was bitterly opposed by the French. Then-president Jacque Chirac refused to take part and publicly fell out with prime minister Tony Blair and president George W Bush over the conflict.

However, the intervention in Libya last year was an example of the two countries working well together in an air and naval operation.

The upcoming presidential election in France might be the first sticking point. A socialist win, pushing Mr Sarkozy aside, might result in a different stance on French foreign policy.

The personal relationship between the two leaders could also be an issue.

Mr Cameron's decision to block the EU treaty last year was extremely unwelcome in Paris.

Ex-French president Charles de Gaulle once said: "Treaties are like roses and young women - they last while they last."

The architects of this latest military treaty will hope he was wrong.