Natural gas flowed directly from Russia into the European Union for the first time on Tuesday, after the German chancellor, Angela Merkel, and Russian president, Dmitry Medvedev, formally opened the Nord Stream pipeline linking the two countries under the Baltic Sea.
As the first Russian gas reached the German mainland at the north-eastern town of Lubmin, Ms. Merkel said the €7.4-bn ($10-billion) project was a sign that Germany was "expecting a safe and resilient partnership with Russia". Mr. Medvedev said the dual pipes, the second of which will be finished next year, marked "a new page" in relations.
The six-year project, kick-started through a 2005 accord between Russia's then-president Vladimir Putin and Germany's then-chancellor Gerhard Schroder, remains controversial, as it could increase Europe's dependence on Russian gas while reducing Russia's reliance on traditional transit countries such as Ukraine.
When Russia started to pump gas into the pipeline two months ago, Mr. Putin, now prime minister, warned Ukraine in particular that "the temptation to benefit" from its "exclusive position" would now end.
Ukraine is yet again in dispute with its eastern neighbour over gas prices, prompting fears that supplies to western Europe might again be disrupted as they were in 2006 and 2009 during disputes that won over some of the Nord Stream project's early critics.
Ms. Merkel on Tuesday said the European Union and Russia would "remain linked" in their energy partnership for decades, despite efforts by EU governments to diversify their energy sources from fossil fuels to renewable forms. Having decided to phase out nuclear power by 2022, Germany will need more gas in the coming years.
When fully operational in 2013, Nord Stream will carry some 55 billion cubic metres of gas -- enough for 26 million households -- into Germany, from where it will be piped to the Netherlands, Denmark, France and the UK. That compares with an export capacity of 150 billion cubic metres annually for Ukraine, Russia's principal supply line to the EU. About 80 per cent of Gazprom's supplies to western Europe currently pass through Ukraine.
The EU's energy commissioner, Gunther Oettinger, reminded the political leaders present at the opening ceremony on Tuesday that the EU was working to secure natural gas supplies from countries other than Russia. These include Norway, Qatar and countries in central Asia, which could be linked to western Europe by Nabucco, a rival pipeline still being planned.
The Dutch prime minister, Mark Rutte, said Nord Stream had come in the nick of time, as EU gas demand was set to pick up over the next few years. His French counterpart, François Fillon, spoke of "a new artery" that would help France complement nuclear and renewable sources with the stability of supply offered by natural gas.
Another guest in Lubmin was Mr Schroder, who in 2006 became chairman of the Nord Stream consortium, which is dominated by Russia's Gazprom but includes Germany's Eon and BASF, Dutch Gasunie, and France's GDF Suez.
He has always defended the move, saying he was there to look after German and EU interests.