This absorbing book is sub-titled: “Life and Death under the Nazi Occupation 1940-1944.” Its author, a well-known American journalist and broadcaster, divides his time between London and Paris and so is appropriately situated to tell the story of those of his compatriots who chose to remain in Paris after the fall of France. The Germans marched into the capital on 14 June 1940. Glass tells us that “at this scene, Parisians had stared, sullen and silent, many of them weeping.” Most American expats had fled; those who stayed were in a difficult rather than an immediately dangerous position – at least until 11 December 1941 when Hitler declared war on the US and they became enemies overnight.

Glass builds his narrative around four prominent personalities whose attitudes towards the Germans were in sharp contrast to each other: the millionaire businessman, Charles Bedaux; Sylvia Beach, owner of the celebrated bookshop Shakespeare & Company; Clara Longworth, Comtesse de Chambrun, who had married into an aristocratic family descended from Lafayette; and Dr Sumner Jackson, who headed the team of doctors at the American Hospital. They had three options under their new and unwelcome masters: to resist, to collaborate or to endure. Sumner Jackson chose resistance, Sylvia Beach endured, Bedaux collaborated – although, as Glass shows, this involved many grey areas – while the Comtesse in her imperious fashion did a bit of all three.

The author provides much detail on the backgrounds of these four people, in order to explain why they behaved as they did in the “moral maze” that the Occupation caused. He tries to understand rather than condemn, leaving the reader to make up his/her own mind with the implicit question hovering in the background: would I have behaved differently in those circumstances, faced with the same moral dilemmas; would I have chosen suffering and privation or to save my own skin?

Bedaux, a self-made millionaire and a brilliant entrepreneur, continued doing business as usual with everyone, French, American – and German. His social milieu included Nazi officials, rising collaborators and newly rich black marketeers. Working for Germany as well as France “he convinced himself he was doing nothing wrong.” French-born but a US citizen, he committed suicide in 1944 when awaiting trial in America as a spy. Yet this man had also endangered his wealth and his life to protect Jewish friends, employees and clients.

Sylvia Beach “hadn’t the energy to flee”, as she admitted. The friend of Joyce and Hemingway, she had run her famous bookshop, a haven for the avant-garde, for 20 years; now she slept in the back of the shop surrounded by books but with no running water, little heating and dwindling food supplies. In this, of course, she resembled most of the population of Paris. When America entered the war she was interned and Shakespeare & Co was forced to close; it never reopened.

Sumner Jackson, the surgeon, had married a Frenchwoman. Deserting the American Hospital was unthinkable; so was compromise. He emerges as a quiet, brave, unflinching man, trying to alleviate the sufferings of French prisoners of war and facilitating their escape. Risking his own life he falsified hospital records to say that these prisoner patients were terminally ill or had died. Eventually sent to Germany as a slave labourer he was to die during an Allied bombing raid.

Clara de Chambrun was perhaps the most complex of the four. Her son had married the daughter of Pierre Laval, deeply unpopular premier of Vichy France; this itself did not make her an actual collaborator but the close association was to tarnish her reputation. But she, too, fought her own battles to keep open the American Library in Paris when it was the only public institution in German-occupied Europe where books in English circulated freely. (She was also a famous Shakespeare scholar and an early investigator of his Catholic influences.) She was keen on maintaining law and order and thus disapproved of the Resistance fighters, believing they made a bad situation worse due to the brutal German reprisals against their activities. While she saw Petain and Laval as “protectors” of France, to others they were traitors. Glass reminds us that the Vichy government sent a million men to forced labour in Germany and helped in the mass deportation of the Jews.

Much of the frenetic atmosphere of those times has been captured in Suite Francaise, the superb (and tragically unfinished) novel of Irene Nemirovsky, one of those deported Jews; she was to die in Auschwitz. American diplomat George Kennan, an observer of the invasion, wrote in his diary: “When the Germans came, the soul simply went out of it [Paris] and what is left is only stone.” Glass, with great sympathy and careful research, has helped those stones to speak.

Francis Phillips writes from Buckinghamshire, in the UK.