Oksana Dyka sang at the 2005 inauguration of President Viktor Yushchenko (or so Wikipedia confidently assures me). Only two months afterwards, she would star in her very first Tosca. Nine years later, in a political maelstrom where power is wrenched from fist to fist daily, where religion cannot be a safe refuge, and where corruption may persecute its casual victims on the sly, Dyka’s home country of Ukraine bears a tragic passing resemblance to Tosca’s Rome on 17-18 June 1800. Set with almost manic precision in the immediate aftermath of Napoleon’s empire-changing victory at Marengo – timing so specific, that when the opera opens, news of the victory hasn’t even reached the city yet – Puccini’s opera might be carbon-dated and confined to those two days in Rome, two centuries ago, forever. But, though far from home today, Dyka must surely feel an unsettling closeness between life and art as she enters Tosca’s nightmare world of political and social explosion.

Dyka’s house debut at Covent Garden in this marvellous production by Jonathan Kent was, nevertheless, a little stiff. Crucially, beyond the odd fizzle which hardly seemed worth dying for on either side, there seemed not much in the way of chemistry between her and her dashing Mario (Roberto Alagna). Puccini gives his principals very little time or space to establish their emotional credibility here: Cavaradossi and Tosca have just one love scene, and we never actually see them alone together (even as they meet in the church, Angelotti makes a silent third, unbeknown to Tosca). Still, this atmosphere of constant supervision is appropriate in a police state gone feral; and Puccini helps with some of his most luxuriously lyrical love music. Love for man, for woman and for God at its most intoxicating, shot through with lust, jealousy and ultimately despair, fuels their every duet. It is possible and indeed fundamental that we believe in their passion from the start; unfortunately, it was just difficult to believe in it this time around.

Occasionally, Dyka acted with a natural felicity and energy of gesture which was a joy to see. At other times, she seemed turgid, almost clumsy on stage. Had the dagger been misplaced, or was it Andrew Sinclair’s decision that Tosca should search the table fruitlessly before finally snatching it to stab Scarpia in one flurried movement? It certainly created tension: as Scarpia prowled ever closer, I found myself scanning the table for that dagger with almost as much desperation as Tosca herself. Still, her murder of Scarpia should be a fierce, glorious moment of defiance, no mere defensive impulse. Tosca’s proud premeditation in this scene (as portrayed by Sarah Bernhardt) was one of the very features which drew Puccini to adapt Sardou’s play. It felt much more like Dyka simply couldn’t find the dagger. The ravishing aria “Vissi d’arte” was rushed in its early phrases – surely, a crime! – though Dyka then settled into a tender and believable rendition which made you wonder why she hadn’t just sung it like that from the start. Later, she walked to her death without a tremor, but also without the self-possession of a queen: she simply walked. This pallid performance sadly overshadowed her otherwise accurate and lyrical singing.

Roberto Alagna, every inch the handsome hero, sounded a little harsh in his earliest phrases, but soon brought warmth, power and depth to Cavaradossi, a part which he seems made for. His “Tosca, sei tu” was spine-tingling: still, in general, he seemed infinitely more in love with her when she wasn’t onstage. Of his political and factional fervour there was no doubt, making for some dynamic masculine pairings with Angelotti (the charismatic Michel de Souza) and versus Scarpia; but if Cavaradossi is not a lover first and foremost, what is he?

Marco Vratogna made a good old-fashioned Scarpia of the seriously menacing variety. Crucially, his moments of sensual abandon were just as unnerving as his threats: I was reminded irresistibly of a Don Giovanni gone sour as he breathed in Tosca’s scent from a stolen hair ribbon. In this most traditional of productions (brilliantly designed by Paul Brown), where a chapel is a gilded, candlelit cage and later a vast Archangel Michael towers over Tosca and her victim, a black-souled villain is just what’s needed, and Vratogna delivers a brilliantly rapacious, calculating predator. Bryn Terfel may bring more inner torture to his Scarpia when he takes over the role.

The smaller roles are all strong. Martyn Hill is an obsequious and well-drawn Spoletta, Jeremy White a wonderfully curmudgeonly Sacristan who bustles and blusters with much charm, and Jihoon Kim gets only too little airtime as Sciarrone, his delicious bass increasingly recognisable. The Royal Opera Chorus sound fabulous in the great liturgical scene closing Act I.

Conductor Oleg Caetani also made his debut on the same night as Dyka; amid much assured orchestral playing, some phrases sounded a little stiff or rushed. Perhaps the problem is that Tosca – dear, historical, familiar, shocking Tosca – has taken a step over the centuries, leapt down from her parapet, and suddenly come much too close for comfort.