What is happening in the SNP?

They are having a defence review and the leadership wants to change policy so that an independent Scotland would remain in Nato. The party's CND activists are meeting in Glasgow today.

What is Angus Robertson proposing?

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 like Sweden, Finland, Austria and Ireland.

What does Jamie Hepburn's amendment say?

No change to current policy, which is to withdraw from Nato after independence.

What's the difference between Nato and Partnership for Peace?

Nato is a full-scale military alliance of 28 states, founded in 1949, and based on the concept of collective nuclear defence. Most EU countries are members, as are Norway and Iceland.

PfP is a Nato programme established in 1994 as a looser alliance, with each of the 22 member countries choosing the extent of its participation.

Why is this such a sensitive issue for the SNP?

Removing Trident is a touchstone for party activists and any reference to this at party conference is cheered to the rafters. Some fear that a U-turn on leaving Nato is a precursor to softening the line against nuclear weapons.

But isn't "healthy debate" a good thing at party conferences?

Up to a point, but no political leaders like courting defeat or looking as if their party is split.