The SNP has signalled a policy U-turn by confirming its aim to pull Scotland out of Nato could be ditched.
Defence spokesman Angus Robertson will ask delegates at the October party conference to support a motion saying an independent Scotland would maintain membership of Nato.
The party’s opposition to Nato stems from its ambition to remove nuclear weapons from Scotland, and the motion will be controversial with rank-and-file members.
Mr Robertson said continuing Nato membership will be ”subject to agreement on withdrawal of Trident from Scotland.”
He also noted that RAF Leuchars would remain an airbase in an independent Scotland under the SNP.
He called the October resolution the ”first significant defence policy update in 10 years, which at its heart prepares for better defence decision-making in Scotland.”
Current SNP policy favours ”cooperation with international alliances such as Nato through its Partnership for Peace programme while not being a member.”
The new resolution states: ”An SNP Government will maintain Nato membership, subject to an agreement that Scotland will not host nuclear weapons and Nato continues to respect the right of members to only take part in UN-sanctioned operations.
”In the absence of such an agreement, Scotland will work with Nato as a member of the Partnership for Peace programme.”
The Nato resolution will be part of a wider foreign, security and defence policy update, which will be put to the vote in Perth between October 18 and 21.
It also includes a financial commitment of £2.5 billion for defence and security, equating to 1.7% of total Scottish GDP, and a proposal for 15,000 regular armed forces.
Conservative leader Ruth Davidson described the Nato resolution as ”staggering” coming from a party ”so furiously against the concept of nuclear deterrent.”
Scottish Labour’s shadow defence minister, Gemma Doyle, said: ”The SNP do not have proper answers when it comes to one of the most important issues facing our country the defence of our nation.”