The barbaric slaughter of the innocents in Madrid and the insane assassination of a slaughterer, Sheikh Ahmed Yassin, find me unable to think of anything except mourning, and despairing of human stupidity. But I would like to write a speech for Tony Blair in which he addresses his words to those who kill, a speech that would ask simple questions such as: "Why do you turn your frustrations, resources and intelligence towards killing and destruction, rather than towards educating yourselves and building your cities? It is so much easier to destroy and cause havoc. Yet every stone thrown could have been a brick laid. It is alluring to scream in the streets and wave guns. But for every scream, you have missed a moment to study and learn about your neighbour. It is tempting to fall in love with yourself being angry - far less glamorous to read a book, far more difficult to think for yourself. It is easy to shout slogans and burn flags, but aren't these empty gestures? We question our leaders, we teach our children to question our leaders. Do you? And if suicide-bombing earns you a special place in paradise, why don't your leaders also want to earn a place in paradise? Do you ever stop to think you are being manipulated by those who do not have the courage to do what they are urging you to do? You know the existence of Israel is not the cause of your anger - Arabs were killing Jews long before the State of Israel came into existence. What do you hope to achieve? No amount of suicide bombing will stop life going on. Soon you will disgust yourselves with so much slaughter. Nothing comes of hatred. Talk to us."
Before discovering I could write plays, I wanted to be a film director. Before wanting to be a film director, I had ambitions to act. I have no idea if I would have made it as a film director, but I had promise as an actor, and have travelled the world giving readings from my plays perched on a bar stool with a script in my hand. I'm a good reader, but I have no illusion that this makes me an actor. Rather a performer. There's a difference.
Out of the blue at this late stage in my life, aged 71, came an invitation to act. Andy Hay, who had directed my play Denial at the Bristol Old Vic, was now directing TV episodes of Waking the Dead. "There's a wonderful small role that I can just see you doing," he rang to say, "of a charming but ruthless conman." Good God! Was I to feel flattered or distressed? I protested that I couldn't really act. I had a commissioned opera libretto to complete, there were readings and workshops to prepare for, I had started work on my first novel and already too much was distracting me from it. But I succumbed. The lure of "and then Hollywood" overwhelmed.
My handful of lines were e-mailed, and my itchy playwright's fingers went to work at once rewriting them. Aided by my PA, I learned my lines before the contract was signed. We laughed a lot at my attempts to be a charming gangster. The producer thought it prudent that I have a screen test - after all, the camera doesn't like everybody's face. I didn't want to be seen by millions through a lens that didn't like me.
The "screen test" was a mildly humiliating experience. At BBC Television Centre, I announced I was there to see Andy Hay. My attempt to raise myself into the hierarchy failed. "Casting?" I was asked. "Er, yes, I suppose so." "Name?" I had to spell it. I was told to take a seat. Soon a young woman came to collect me. "Casting?" she asked. "Er, yes, I suppose so." "Arnold?" Unearned familiarity always sets my teeth on edge, but I resisted saying "Mr Wesker, please". I was led to another waiting area some ten miles away. What on earth am I doing here, I asked myself, feeling what it was like to be an actor wandering hopefully but forlornly from audition to audition.
Andy found me, and soon I was delivering my lines with him just as I had frequently "read in" alongside actors auditioning for my plays. To add to the mild humiliation was the presence of two casting women in the room, one holding a camcorder. Was my best side being filmed? Did I have a best side? I was being considered instead of considering.
Next day, Andy rang to say they all loved me but agreed that there was another character for which I was better suited. "There's this wise old rabbi . . ." Gangster, wise rabbi - what difference? Just remember, I told myself, the first note you give actors when you're directing: make sense of the lines, the emotion will follow.
The process began. It was both a novel and a familiar experience. Familiar in that I'd sat through a number of my plays being televised; new in that, this time, I was the actor. Andy is good with technicians and actors - patient, jovial, relaxed - knowing exactly what he was doing. Did I know exactly what I was doing? Andy wasn't ploughing me with notes, so I assumed all was well. We had agreed - no beard, no skullcap, no stereotypes. He let me create a mischievous rabbi, and allowed me to wear a bright red scarf.
Everyone works hard in movies - with long, repetitive hours and constant attention to detail. Technicians and actors earn their money. I watch TV drama with a different eye now. I'm available.
Arnold Wesker will be reading from four new works at the Hay Festival (28 May to 6 June)