Papers published by the Foreign Office reveal the extent of Margaret Thatcher's opposition to German unification. As Brian Hanrahan reports, she had an ally in French President Francois Mitterrand, but was at odds with her own foreign secretary.
The fall of the Berlin wall was a moment that brought joy to much of the world, catapulting the issue of German re-unification onto the international agenda.
President Mitterrand [said] the sudden prospect of re-unification had delivered a sort of mental shock to the Germans - its effect had been to turn them once again into the bad Germans they used to be
From memo by Thatcher adviser Charles Powell on lunch with Francois Mitterrand, 20/01/90
But both British Prime Minister Margaret Thatcher and France's President Mitterrand were worried.
Mrs Thatcher feared that by joining East and West Germany, a greater German state would be created which would be too powerful.
From the very start she showed caution.
"We must be immensely grateful to those people behind the Iron Curtain who never lost their faith in liberty," she said.
"But now it's the hard work of building the democracy and then we have to see what happens."
Mrs Thatcher's foreign policy adviser, Charles Powell, recorded her belief that West Germany needed to be checked by its allies.
"The Prime Minister's view is... we do not want to wake up one morning and find that events have moved entirely beyond our control and that German re-unification is to all intents and purposes on us," he wrote on 8 December 1989.
Douglas Hurd looks back to the autumn of 1989 and his disagreement with Margaret Thatcher over German reunification
But Mrs Thatcher, who was used to influencing European leaders, could not convince them of her position on re-unification, even though she argued that re-unification might weaken the Soviet leader, Mikhail Gorbachev.
Even her Foreign Secretary, Douglas Hurd, disagreed.
"My only real argument with her during the year that I was her foreign secretary was on the German question, where she certainly felt that the brakes should be applied," Mr Hurd said.
"She felt that partly for reasons about Germany and partly because she felt we must not put Mr Gorbachev at risk."
But the Foreign Office thought there was no hope of blocking Germany's re-unification.
Although Mrs Thatcher bitterly resisted the advice, Mr Hurd gradually wore down her resistance.
Ten weeks later, he noted the following in his private diary after a meeting with Mrs Thatcher:
"Usual diatribe against German selfishness, but the hankering to stop unification now comes less often."
The West German Foreign Minister Hans Dietrich Genscher watched as Mrs Thatcher become more and more isolated.
Hans-Dietrich Genscher: "I personally had the impression there were some differences"
"I personally had the impression that there were some differences between Mrs Thatcher and Douglas Hurd," he says. "He was very constructive and helpful."
While France's President Mitterrand told Mrs Thatcher he agreed with her, he was at a loss as to what they could do.
So Mr Mitterrand gave way gracefully as the German Chancellor Helmut Kohl pressed more forcefully for unification.
When Mr Powell visited West Germany, he wrote the following from Bonn, the capital:
"They are in the driving seat and Toad is at the wheel. The exhilaration is unmistakable. The Germans' moment has come: they are going to settle their destiny."
Patrick Salmon, the Foreign Office historian who compiled the volume of papers published on Friday as German Unification 1989-1990: Documents on British Policy Overseas Section III Volume VII, says Mrs Thatcher's trenchant objections made little practical difference.
"I think you could say she was a very useful lightning conductor, because she was saying things that other people sometimes felt but didn't want to say," he says.
But it was clear that nobody could resist the pressure for this new state.
German politicians could not, and neither could anybody else.
Germany was re-united within the year to popular acclaim.
Its capacity to sweep aside international objections was the first demonstration of its new-found strength.
This page is best viewed in an up-to-date web browser with style sheets (CSS) enabled. While you will be able to view the content of this page in your current browser, you will not be able to get the full visual experience. Please consider upgrading your browser software or enabling style sheets (CSS) if you are able to do so.