The first minister has backed the UK government's decision to upgrade Britain's nuclear deterrent with new submarines to be based on the Clyde.
Submarines at Faslane are equipped with Trident missiles
Jack McConnell said the decision allowed Britain to maintain a nuclear deterrent and therefore enter possible multilateral disarmament talks.
However, the SNP said Mr McConnell was "taking his orders from London" after "months of indecision".
The SNP had previously accused Mr McConnell of dodging the issue.
The Scottish Conservative Party, which said it was 100% behind the UK Labour Party's plans, had questioned whether Mr McConnell would show the same support.
SNP deputy leader Nicola Sturgeon said: "Having sat on the fence for so long, he [Jack McConnell] has now received his orders from London and is duly complying to the letter.
"The first minister has simply rolled over for the prime minister."
Solidarity MSP Tommy Sheridan, a long term campaigner against the Trident nuclear base at Faslane, said: "It's sad to watch those past anti-nuclear campaigners like Jack McConnell and other Labour MSPs squirming to justify their total somersault on this."
The Scottish Greens said the decision would heighten international tensions and waste billions of public pounds.
The prime minister told MPs in the Commons that in the current global political climate it would make no sense to get rid of the UK's nuclear deterrent.
The estimated cost of replacing the Trident fleet with new nuclear submarines would be £20bn, he said.
The SNP outlined a list of services, such as hospitals, schools and transport, that it said the money could have been spent on.
MP Angus Robertson said: "This government will proceed with its warped priority of investing in weapons of mass destruction before better local services.
"Son of Trident would be a bad decision to match Blair's determination to go to war in Iraq."
Giving details of the UK Government's white paper, Mr Blair said the number of warheads would be cut by 20% to fewer than 160 and the number of Trident submarines currently in service may fall from four to three.
Green MSP Chris Ballance said: "Trident replacement is illegal, immoral and strategically ridiculous - and the expected slight reduction in the arsenal is not going to change that.
"This is a crucial economic, strategic and moral issue for Scotland and our voices must be heard.
There was a small protest outside the gates of the Faslane base
"Scotland must resist a move which would make us a terrorist target, would create yet more nuclear waste, would be illegal and would give this country a key role in maintaining one of the most immoral and brutal features of 21st Century politics."
Solidarity MSP Tommy Sheridan said it was a "dark day for Scotland".
"The decision to renew Trident is an obscene waste of money at £22bn initially and possibly up to £76bn including the maintenance cost," he said.
However, the first minister has said that Trident replacement might be part of a new round of arms negotiations with countries like Iran.
His decision to back a new generation of nuclear missile submarines could now become a major issue at next year's Scottish parliamentary elections.
There was a small demonstration outside the gates of Faslane naval base on the Clyde, which is home to Trident nuclear submarines.