Two of the president's initiatives, on disarmament and relations with Russia, have been dealt a serious setback

Barack Obama's hopes of reshaping US foreign policy stand on the brink of failure tonight, after two of his most cherished initiatives — nuclear disarmament and better relations with Moscow — were dealt serious setbacks.

According to a leaked Nato document seen by the Guardian, a move to withdraw US tactical nuclear weapons from Europe has been omitted from the alliance's draft strategic doctrine, due to be adopted by a summit this weekend in Lisbon.

Meanwhile in Washington, a Republican leader in the Senate signalled that the nuclear arms control treaty Obama signed in April with Russian president Dmitry Medvedev is unlikely be ratified this year. Most observers say that if the treaty – known as New Start – is delayed until next year, it will be as good as dead, as the Democratic majority in the Senate will be even thinner by then, following the party's losses in the midterm elections.

Together the setbacks mark a new low point for Obama's ambitions, set out in a landmark 2009 speech in Prague, to set the world on a path to abolition of nuclear weapons.

They also rob the president of the main concrete achievement so far in his bid to "reset" US-Russian relations. In the absence of progress in the Middle East or Iranian compromise over its nuclear ambitions, the developments threaten to eclipse Obama's legacy in foreign policy.

"All this stuff was integrated – the nuclear package and the Russian relationship," said Steven Clemons, policy analyst at the New America Foundation. "In terms of the long-term international significance it's the most important thing Obama has done, and it has just come apart."

In the latest draft of Nato's "new strategic concept", seen by the Guardian, nuclear weapons remain at the core of Nato doctrine, and an attempt to withdraw an estimated 200 American B-61 nuclear bombs from Europe, a legacy of the cold war, is not mentioned.

Germany, the Netherlands and Belgium – who all have B-61 bombs on their soil – had pushed to have the tactical weapons removed, with the encouragement of supporters of disarmament in the Obama camp including the US ambassador to Nato, Ivo Daalder.

However, in a victory for France, which led a rearguard action against diluting nuclear deterrence in Nato doctrine, the draft strategic concept states that the weapons would only be removed as a trade-off with Moscow.

"In any future reductions, our aim should be to seek Russian agreement to increase transparency on its nuclear weapons in Europe and relocate these weapons away from the territory of Nato members," the draft states. "Any further steps must take into account the disparity with the greater Russian stockpile of short-range nuclear weapons."

Advocates of disarmament still hope the door to withdrawal could be left open in another strategic review, possibly next year.

But Daryl Kimball, the head of the Arms Control Association, said the Lisbon document represented a lost opportunity for the alliance.

"Nato does not need these weapons against any of the 21st century threats we face," Kimball said. "The weapons raise the risk of nuclear terrorism, and their presence makes it harder to convince Russia to cut its own tactical arsenal."

US and Russian negotiators had been expected to discuss tactical weapons in the next round of arms control talks, but those talks will almost certainly not take place if the New Start treaty is shelved.

The White House had hoped the Senate would ratify the treaty in its lame-duck session currently underway, before newly-elected Republican senators take their seats in January.

However, the administration still needed some Republican support to get the 67 votes required for ratification. In a last-ditch move last week, it offered to spend an extra $4 bn (£2.5 bn) on modernisation of the existing nuclear arsenal — an effort to placate the Republican whip, Jon Kyl.

However, Senator Kyl issued a statement tonight saying he still did not think the treaty could be passed in the lame-duck session, "given the combination of other work Congress must do and the complex and unresolved issues related to Start and modernisation." Some Democrats were still hoping tonight the statement could be a bluff aimed at extracting yet more funding for America's nuclear labs. Others, however, saw it as a slammed door, and a reflection of Republican determination to make Obama a one-term president and erase his legacy.

Paul Ingram, head of the British American Security Information Council (Basic), said Obama's radical vision of "a world without nuclear weapons" laid out in his Prague speech was now fading.

"I wouldn't say it was dead. It's in emergency resuscitation," Ingram said.

"If there is hope no, it's not coming from Washington. The leadership of this is not going to come from Washington."