After the war, Lileikis had worked in East Germany for the CIA in providing information on Communists, for which he was rewarded by entry into the US and the award of American citizenship. Proof of his former position was insufficient for legal purposes. The OSI needed documentary evidence of his involvement in sending Jews to their death in the forest killing ground at Ponary outside Vilnius. Eventually, during one of 16 visits to examine archives in Lithuania, a multilingual OSI researcher, Mike McQueen, tracked down a whole set of Lileikis's signatures on deportation orders. These overcame Lileikis's denials and Fifth Amendment pleas, but they were insufficient to satisfy the court in Lithuania.

The Nazis Next Door ends with a telling epilogue befitting the 70th anniversary memorial of the liberation of Auschwitz, which is likely to be the last significant commemoration when more than a handful of survivors are still alive. In 2014, the US authorities arrested one of the last Nazis still living in the US: Johannes Breyer, aged 89,  was charged with taking part in the gassing of 216,000 Jews at Auschwitz. On the very day he was ordered back to Germany, he died.

So what is the future of Holocaust commemoration when perpetrators, witnesses and surviving victims are no more? The answer in various countries is to establish museums, to make a last effort to video-record survivors' testimonies, to establish an annual day of remembrance, and to fund educational schemes such as the regular visits to Auschwitz arranged in the UK by the Holocaust Educational Trust.

These all are worthy and necessary. However, they are not sufficient to overcome the misunderstanding of the Holocaust which is the legacy of the Cold War. Moreover, public schemes and monuments have pitfalls. They all too easily become glossy, simplistic presentations and provide career opportunities for some highly- paid professionals. The director of one Holocaust memorial in the US had a yearly salary package in 2012 of nearly $600,000.

There are several unresolved issues to be addressed.

First, while survivors of Nazi atrocities remain alive, the world community and world Jewry in particular has a responsibility to ensure that they are not left in serious material need or without proper healthcare. In countries ranging from Israel to Lithuania, elderly victims have been neglected.

Second, records of intelligence agencies from the decade after the end of the Second World War need to be made available regarding the use in the Cold War of former Nazis. In the US, the Nazi War Crimes Disclosure Act was signed by President Clinton on October 8, 1998. The inter-agency working group established to supervise the declassification process included James Crichelow, the former CIA officer directly responsible for the policy of recruiting former Nazis to the Gehlen Organisation, the fledgling West German foreign intelligence agency. It is not surprising that the declassification was incomplete. Nevertheless, it produced useful results summarised in various publications.

There is an urgent need for similar declassification by the UK. The case is strengthened by reliable indications that British reluctance to reveal postwar dealings with former Nazis has prevented release of information by other countries. Intelligence agencies are particularly hesitant to publish details of agents employed by sister agencies, even in the distant past.