By Caroline Wyatt BBC Moscow correspondent

The 11 September attacks changed the political map of the world in many ways - not least in the relationship between Russia and the West.

The Russian President Vladimir Putin proved an unexpectedly staunch ally for Washington, and a new, closer relationship grew up between Mr Putin and the US President George Bush.

"Even during the Soviet Union, we always knew that Texas was the most important state in the USA." Uproarious cheers from Vladimir Putin's Texan audience followed his jokey introductory remarks during his first visit to the home of George W Bush after 11 September.

But his speech wasn't just full of diplomatic niceties. The dialogue between the two presidents was also a sign that at last, Vladimir Putin and George Bush were on the same wavelength.

Sympathy

Their question-and-answer sessions during Mr Putin's visit to the US showed that on many issues, Moscow and Washington were suddenly speaking the same language.

Since 11 September, their relationship has flourished.

Mr Putin will have to show strong leadership if he is to resist internal pressures and stand by the US

First, Mr Putin rang the US President on 11 September to express his profound sympathy - and to ask how Moscow could help. In the following months, Vladimir Putin allowed US troops and airbases into Russia's backyard - onto what had been Soviet soil in Kyrgystan and Uzbekistan.

He did so against strong objections from his own ministers and advisers, who said such a move could provoke deep unrest in Russia's military and unease among the public.

Yet the march of US troops into Central Asia has only enhanced Mr Putin's standing in the West, as George Bush made clear as he welcomed him to Texas.

"When I was in high school, Russia was an enemy," Mr Bush said. "Now the high school students can know Russia is a friend.

"We're working together to break the old ties, to establish a new spirit of co-operation and trust, so that we can work together to make the world more peaceful.

"Russia has been a strong partner in the fight against terrorism."

Closer ties

When Mr Bush arrived in Moscow earlier this year, President Putin made clear the feeling was mutual.

"It's totally obvious," he said "that today we are speaking the same language when we discuss global terror and the challenges that face us."

As long as Mr Putin carries on improving living standards at home, the Russian public is happy to accept this new closer relationship between former Cold War enemies - even though the legacy of Cold War suspicion of America remains strong for many Russians.

But others - inside the Kremlin and Russia's military establishment - are less convinced.

Older Kremlin powerbrokers still see the US as a potential enemy, and want Russia to continue to exert its own imperial influence over various parts of the globe - including keeping close ties with Iran, Iraq and North Korea, all part of George Bush's "axis of evil".

Long-term allies

Mr Putin already faces difficult choices on Moscow's attitude to Iran and Iraq. Russia is helping Tehran build a nuclear reactor in Iran at Bushehr, a project worth $800m.

Washington has asked Russia to withdraw from the project because of fears that Iran will be able to use the technology to build weapons of mass destruction.

Russia has so far insisted it will continue the work. Similarly, Moscow has been a long-term ally of Baghdad, and vehemently opposes US military action in Iraq.

Over the coming months, that test of loyalties will become increasingly tough for the Russian president.

Mr Putin will have to show strong leadership if he is to resist those internal pressures and stand by the US, keeping the new Russia firmly on the side of the West.