There can be few marriages quite as strange or as burdened by history as that of the German politician Vera Lengsfeld and her former husband, who spied on her for the East German secret police. “I have forgiven him,” the 54-year-old former dissident said. But she made it clear that personal forgiveness was as complex as the uneasy unification of Germany.

This, after all, was no conventional marital betrayal — no fling with a neighbour or office romance. Every halfway political conversation, every dinner with friends became the subject of a report to the Stasi.

“Now we have to see if he wants to meet me again,” she said. We are sitting in a corner of the high-walled Hohenschönhausen prison in Berlin, one of the most notorious of Stasi jails that is now an open museum. Ms Lengsfeld has just shown me her old cell and the exercise yard, seven paces long, five paces wide. Prisoners were deliberately subjected to radiation. “Thousands were psychologically destroyed,” she added.

“When we were fingerprinted, we had to sit on a piece of fabric. This was later placed in an airless jar because they wanted to capture our smell. Can you tell me why?” The jars were later discovered in the Stasi cellars. Ms Lengsfeld’s husband, Knud Wollenberger, codenamed Donald by the Stasi, had tried to warn her not to attend a peace rally in 1988. Today it is clear that he knew from his Stasi masters that the woman he claimed to love, the mother of his two children, was about to be arrested.

After a humiliating month in the jail, Ms Lengsfeld was expelled from the country and spent time as a philosophy student in Cambridge. Only after the Berlin Wall collapsed did she discover that her husband had been informing on her during much of their marriage. They divorced and have not spoken since.

Mr Wollenberger has sent his former wife a letter explaining that he wanted to shield her and claiming that his betrayal was, in fact, an act of love.

It is an old story: so old that Hollywood got wind of it and considered Meryl Streep to play the role of Ms Lengsfeld, but it has gained sudden new relevance. Mr Wollenberger is seriously ill. “He has a galloping form of Parkinson’s and stays all day in a darkened room,” Ms Lengsfeld said. The time for a final reconciliation is fast approaching; the end of a small but traumatic episode in East-West German history.

It is a symbol, too, of the unfinished business between the two halves of a supposedly united nation. Ms Lengsfeld is a Christian Democrat deputy and a serious conservative thinker. Chancellor Merkel is the leader of her party and a fellow East German. But Ms Lengsfeld said that the Chancellor had betrayed the libertarian principles of the 1989 revolution that helped to topple the communist regime.

By forging a grand coalition with the Social Democrats, Mrs Merkel had diluted her commitment to strengthening the freedom of the individual. Socialist orthodoxies — above all an obsession with subsidies, public borrowing, political intervention and an overpowering bureaucracy — were crippling the German Government, however superficially successful its performance.

“The Chancellor has disappointed us,” Ms Lengsfeld said. Her dismay was rooted partly in Mrs Merkel’s unwillingness to be tougher with well-cushioned former communist bureaucrats. “A third of the transfers to east Germany are going towards the pensions of these people. That’s ridiculous,” Ms Lengsfeld said.

The men and women who served as her warders, even as the prison governor, still live in an estate close to the notorious jail. Others tried to block Ms Lengsfeld’s attempts to put memorial plaques in the security zone around the prison walls. Almost every public discussion about East German history is barracked nowadays by a group of determined communist hecklers.

The old East German state refuses to lie down and die, and that angers the likes of Vera Lengsfeld. She may be ready to make her peace with a husband who was manipulated by the regime — but not with her former jailers.

Watching you, watching me

• The Ministerium für Staatssicherheit, the Stasi, was founded in 1950 with the motto “Shield and Sword of the Party”
  
  
• In its 40-year history it employed 274,000 people; it had a staff of 102,000 in 1989 and infiltrated almost every part of East German life
  
  
• After the collapse of the Berlin Wall in 1989 angry citizens stormed its offices and arrested officials, who had by then shredded hundreds of thousands of incriminating documents
  
  
• Thousands of archivists have attempted to piece together the documents
  
  
• A decade after the fall of Communism, 3.4 million citizens had asked to see their files
  
  
• Since 1989, 180,000 people have been identified as informers, although the real figure is likely to be higher
  
  Source: Times archive, The New York Times

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