I was the youngest of four brothers. The two eldest were twins, many years older than I. On the outbreak of the second world war, the twins volunteered to join the Royal Air Force as aircrew. They must have been 17, or at most, 18 years old. They never consulted our parents. It was their decision entirely. When my parents learned about it, my father tried to persuade his sons to join something less dangerous – the army, or perhaps as RAF ground crew – but Basil and Gerald wouldn't listen. They said that if everyone went for the less risky options, there would be no RAF. They were determined to fight for their country and felt especially that, as Jews and knowing something of the persecution going on in Germany, they should be prepared to fight and take high risks. My father begged them to change their minds, but they refused.

Basil and Gerald could both have trained as pilots and become commissioned officers, but this would have taken too long. I remember hearing from my older brother, Denis, the third son, that one of the standard questions potential officers were asked by the interviewing board was: "What newspaper do you read?" It clearly implied that only those who read acceptable broadsheets such as The Times or The Daily Telegraph were fit to be officers. This infuriated Gerald, who responded: "The Daily Worker" – the official organ of the Communist party. The interview was terminated shortly thereafter.

The truth was that neither Basil nor Gerald gave a damn whether they were officers or not. What they cared about was getting at the Germans as soon as possible. Basil chose to train as a navigator, Gerald as a bomb-aimer (the shortest training course and, together with air gunner, probably the most dangerous role in a bomber aircraft). When he came home on occasional weekend passes between bombing operations, he never spoke of his experiences and I suppose my parents never asked. I can imagine their feelings, knowing that in a few hours he would be flying over Germany again.

In March 1943, my parents received a telegram. "The air ministry regrets to inform you ..." Gerald was missing. They were, of course, devastated, though for some time they clung to the hope that Gerald had bailed out of his Halifax aircraft and been taken as a prisoner of war. It is the custom among Jewish people to "sit Shiva" for one week on the death of a member of the family. Shiva is the Hebrew word for seven. The family remain at home for seven days, and friends and relatives visit them to offer what comfort they can. Today we call this closure. For my parents there was no closure. Since there was no proof that Gerald had died there could be no Shiva. They were deprived of even this crumb of comfort. The word "missing" hung like a sombre cloud over their lives. In time, my parents, slowly and painfully, were compelled to accept that Gerald would never come home.

Told that Gerald was missing, Basil did not react immediately. After a few days, he wrote a wonderful letter to my parents (which I still have), in which he told them Gerald's favourite quote was from The Count of Monte Cristo by Alexandre Dumas: "Until the day when God shall deign to reveal the future to man, all wisdom is summed up in these two words – wait and hope."

Basil was posted to Scotland to train others in navigation and was away for some time. He wrote a letter to Denis in which he told him: "You have lost a brother – I have lost half of myself." Eventually, he came home on leave, which was extended when he was told by the air ministry that he was on embarkation leave – the last home leave for troops scheduled for foreign service. Denis had to tell my parents, who inevitably were heartbroken.

The war ended in Europe and everyone hoped for a speedy end to the one in the far east. (Basil was in India flying missions from an airstrip near the border with Burma, then occupied by the Japanese). A few months before the end of that war, a telegram arrived from the air ministry: Basil had been killed. As a result, my father was a broken man; my mother spent months in hospital and very nearly died, surviving only when she was reminded she still had two sons who needed her.

Basil's plane (a Mosquito, made almost entirely of wood) had been hit. His pilot, the squadron commander, had wanted to bomb Japanese positions from a height, but Basil insisted on low-level strafing, a decision that cost him his life. He was hit in the face by a shell, the pilot managing somehow to bring the plane back. Soon after it landed, Basil died of his wounds. The pilot visited my parents and told them exactly what had happened. I sat with them and witnessed their suffering. Young as I was, it was a day I shall always remember with pain.

The death of the twins changed my parents. They were never the same again. And they never talked about it. None of us did. I remember when I was older asking my mother to tell me something about the twins. She recalled walking them in a pram in a park when they were babies. It was as if they were still alive for her. I also remember wondering why she always cried when she heard the song Somewhere Over the Rainbow. Years later, a friend of hers told me why. Early in the war, we had moved to a cottage overlooking the Sussex downs, to be near where the twins were training. My mother used to go ice-skating regularly, and whenever the twins were given a pass out they would come and watch her skate. This was not long after the film The Wizard of Oz was released. Somehow, in my mother's memory, Judy Garland was always singing that song when her two boys came home.

The loss of my brothers affected me in an odd way. I was always a bit of a dreamer and I think that, in some way, I found it hard to accept that what happened was real. Certainly, the feelings attached to loss were not real. But as the years passed, it became only too real, and more and more difficult to live with. I'm sure I had survival guilt. My brothers were heroes and what was I? Nothing. Or nothing that I could respect the way I respected them. Would I have volunteered for aircrew in their place? Probably not. I tried to block it all out and for a long time became introverted and unsociable. I had closed the feelings shop.

I rarely talk about the twins. Somehow it is never the right time. But some years ago, I was having lunch with a business acquaintance who asked if I had any siblings. I said I had one older brother. I then added that I also had two much older brothers who were killed in the war. He looked astonished and, after an embarrassed pause, said: "I didn't think Jews fought in the war."

Those words were like a blow to the stomach. I told him that many Jews had fought for their country in the war – according to AJEX, the Association of Jewish ex-servicemen, 60,000 British Jews fought in the second world war, almost the same percentage as every other section of the community.

My brothers, Basil and Gerald, were men of conscience. In mankind's long history, never had the issues been so clear cut. They were fighting an evil regime that had to be destroyed, and to do that they were ready to sacrifice everything.

You might think that, as the years pass, the memory would dull. But it doesn't. Quite the contrary. I think about my brothers more than ever, almost every day, even though I hardly knew them. The memory burns like fire. And it never goes out. Had they been less brave and less idealistic, they might have been alive today. I can't help imagining all the things they would have done – the rich, full lives they would have led, the children they would have had ... my nephews and nieces. They were highly motivated, brave young men – and they had ideals. They fought for a cause they believed passionately in. And they died for it. I am enormously proud of them.

The Call of Destiny and The Hour of Camelot, by Alan Fenton, are published by Dovecote Press, £8.99. To order a copy of either book for £6.30, with free UK p&p, go to theguardian.com/bookshop or call 0330 333 6846