William Hague was given a warm reception by Tory members
Progress in Afghanistan would be a Conservative government's first foreign policy priority, shadow foreign secretary William Hague has said.
He told the party's conference in Birmingham failure would leave the world more open to terrorist attack.
Among its first acts would be to set up a full Privy Council inquiry into the origins and conduct of the Iraq war.
And he said the West should show "the strength of united resolve" in dealing with Russia.
In his keynote speech Mr Hague told party members: "Progress in Afghanistan, and in the closely related problems of Pakistan, is the single most urgent focus in foreign affairs for our work as a new government."
He said they would urge the US to "intensify the efforts to turn tactical successes into strategic victory, requiring as that does a functioning, non-corrupt government in Kabul, the better co-ordination of aid and a unified military command".
While the party had struck up a good relationship with both US presidential candidates, the Tories would have a "solid but not slavish" attitude to Washington, he said.
He said if Labour did not set up a full Iraq inquiry, it would be one of the first acts of a Conservative government.
The Conservatives supported the war in Iraq, but Mr Hague said: "We all know that an occupation of Iraq that was better conceived and implemented could have spared so many the agony and bloodshed of the last five years."
The prime minister of Georgia, Lado Gurgenidze, was at the conference where he won a standing ovation from party supporters. Party leader David Cameron visited Tbilisi at the height of Georgia's conflict with Russia.
Mr Hague said Britain would not "seek quarrels with Russia" but said the West had to be united in dealing with Moscow.
"In dealing with any nation that turns its back on the peaceful resolution of disputes, history has taught us that weakness can never be the way," he said.
To cheers he also repeated his pledge that a Conservative government would hold a British referendum on the EU Treaty, if Ireland does not reverse its own rejection of the treaty.
But he stopped short of pledging a poll if the treaty had been ratified by the time a Tory government took power.
It would "set out at that point the consequences of that and how we would intend to proceed," he added.
The treaty was drawn up to replaced the EU Constitution - on which Labour had promised a referendum - after that was rejected by French and Dutch voters at referendums in 2005.
The Conservatives argue it is essentially the same and should also have been subject to a referendum in Britain, but the government said it was different and did not have constitutional implications.
The treaty, which is designed to streamline decision making in an expanded EU, was officially ratified by the UK in July.
But Ireland, the only EU country to hold a referendum, has rejected it. All EU states must ratify it before it comes into force.