As he lay dying in a London hospital, Alexander Litvinenko expressed total conviction about the identity of his killer: “The howl of protest from around the world will reverberate, Mr Putin, in your ears for the rest of your life.”

Litvinenko, a fierce critic of Vladimir Putin’s rule, was poisoned with polonium three years ago this week. He suffered a terrible, lingering death. Yet, contrary to his prediction, the protests have long subsided. David Miliband is in Moscow, on the first official visit by a British Foreign Secretary for five years.

A full British electoral cycle is an age in politics. The justification for the visit is that there are pressing pragmatic reasons for trying to gain Russian assent to Western nations’ security goals. British protests have gained little understanding, let alone concession, from the Kremlin. Yet symbols matter in diplomacy, and the symbolism here is wrong. Mr Miliband should register with his hosts more than formal displeasure at Russia’s obstructionism in the Litvinenko case. He should point to the pattern of Russian diplomacy that undermines Western efforts to promote collective security. Russia is a brute fact of international diplomacy, it is not an ally.

Russia has obdurately refused to extradite Andrei Lugovoy, the former KGB operative who is the chief suspect in Litvinenko’s murder. The British Government rightly expelled four Russian diplomats in protest two years ago. Moscow’s conduct remains scandalous.

This is not an obscure dispute over an awkward happenstance, in which the demands of realpolitik trump the requirements of justice. Litvinenko was a British citizen. His murder was an act of unspeakable brutality, committed in the heart of London. His fate replicated that of other critics of Mr Putin, such as Anna Politkovskaya, the journalist, who was shot dead in Moscow in 2006. The charge that Litvinenko’s was state-sponsored cannot be refuted, because Moscow has ensured that no trial can take place.

Regardless, Mr Miliband wrote last week: “We don’t always see eye to eye with Russia, but we share the same global challenges and it is important that we work on them together.” This is true but trite. Russia shares an interest with the West most obviously in restraining Iran’s nuclear adventurism. Yet its diplomacy has been inconstant. It has veered between support for the EU-3 (the UK, France and Germany) and refusal to exercise leverage of its own. Delphic hints from Dmitry Medvedev, the Russian President, that Russia might support additional sanctions are no firm evidence of a more constructive approach

However much Mr Miliband desires co-operation from Russia, he cannot wish it into existence. Russia does not provide it. Most brazen is its harassment of small nations on its borders: unilateral recognition of Abkhazia and South Ossetia as independent states last year; and the launch of cyber-attacks against Estonia in 2007. But the provocations are not geographically limited. Moscow’s opening to Hamas in 2006 might have been designed to sabotage Western efforts to foster Israeli-Palestinian peace.

Mr Miliband needs to raise these issues. Litvinenko’s murder cannot forestall the resumption of diplomacy. But nor should it be forgotten and forgiven, for it is emblematic of why relations with Russia are at so low an ebb.