Russia's test launch of an intercontinental ballistic missile, the new Tapol-M with multiple independently targeted warheads, and of the Iskander short-range missile, is hugely significant. For years, Putin's Kremlin has been viewing Nato and US policies with growing concern - policies, it believed, that were encouraged by the humiliation of Russia during the Boris Yeltsin years and fed by the assumption that Moscow could be taken for granted.

There have been plenty of warnings. Putin has repeatedly attacked America's plans to locate anti-missile interceptors in Poland, and a new missile defence radar in the Czech Republic. Washington's insistence that they are aimed at a future threat from North Korea and Iran are beside the point, even if they were privately believed in the Kremlin.

In March, Russia's security council announced that it no longer considered global terrorism as the chief threat, as Rod Thornton of King's College, London notes in the latest issue of The World Today published by the thinktank, Chatham House. The main threat to Russia's security, it said, came from international organisations and structures that were getting stronger, "especially Nato". Then last month Putin froze Russia's obligations under the conventional forces in Europe's treaty, ratified by Russia but not yet by the US on the grounds that Russia still has troops in Georgia and Moldova.

So Putin has signalled not only that it is prepared to use the energy weapon, but military weapons too. The message, says Yuri Fedorov of Chatham House, is: "If the west does not take into account Russian interests as perceived by the Kremlin, then we will deploy the new weapons."

As Russia test-launched its new weapons on Tuesday, Putin warned that if the US went ahead with its missile defence shield in Poland and the Czech Republic it would "turn Europe into a powder keg". Despite the language of rhetoric, the Kremlin now seems prepared to move from words to deeds, say Kremlin watchers.

"It is quite clear the Russians are very seriously worried about the (US) plans for missile defence in Europe," says Oksana Antonenko of the International Institute for Strategic Studies. "They genuinely believe it is directed against them," she says. Russia believes the US and its allies have broken their commitment not to deploy permanent military bases on the territory of new Nato members, she says. And if the US gets its way and deploys missile defences in Europe, America would feel even more confident and "even more prone to adventurism" towards other countries, including Iran.

Washington - at least Condoleezza Rice at the US state department and Robert Gates, the new US defence secretary - appear to be adopting a more multilateral approach, having painfully learned the lessons of going it alone, notably in Iraq. But they need to be rather more convincing than they have been up to now. And it is time Europe - including Britain - took a more active and independent role on the world scene, a moderating influence both on Washington and Moscow. For a new and dangerous arms race is on the cards.

"The Guardian"