Defense and disarmament have become as much a part of the ideological divide in Britain as the welfare state and private enterprise. Clearly the ideological battle lines over defense and disarmament are sharply drawn:
The Conservative Party on the right flank is strong on defense. Britain must have a credible defense policy, it says, and private enterprise increases the financial and social mobility of all Britons.
The Labour Party on the far left flank clamors for disarmament. Much of this sentiment is based on the party's socialist philosophy that argues too much money is diverted to defense at the expense of health, education, and social services.
Occupying the middle ground is the Liberal-Social Democratic alliance, which seeks to strike a balance between Conservatives, whom they judge to to be lukewarm about disarmament, and the Labour Party, which is seen as soft on defense.
Yet if there is one phrase that immediately is a giveaway in deciphering whether political parties are hawks or doves, armers or disarmers, left or right , it is unilateral disarmament.
That is why the decision of the Liberal Party here to call for the immediate removal of American cruise missiles on British soil is easily the most contentious decision taken so far during the current season of political party conferences.
In a fighting speech at a Liberal Party conference fringe meeting right before the crucial defense and disarmament debate, Msgr. Bruce Kent who heads the Campaign for Nuclear Disarmament, urged party delegates to scrap the cruise.
Cruise, he said, was not a deterrent but part of a package that is fighting and winning a nuclear war and should be unconditionally sent home.
''They're totally and utterly under American control. They don't add to our security but increase our insecurity.''
The party conference went on to heed his advice on removing cruise missiles immediately, but approved by a much larger margin a decision to allow multilateral negotiations to pave the way for the removal of Polaris, Britain's independent but aging nuclear deterrent which is to be phased out in favor of the American Trident system.
Asked after the debate whether it was significant that the party had voted against cruise staying, because it was American, and for Polaris to remain pending arms negotiations, because it was British, Andrew Ellis, the Liberal Party's national executive vice-chairman conceded: ''That's a fair comment.''
But he denied the decision was motivated by an anti-American bias. He suggested it was more a feeling for Britons that ''you want to control your own destiny than have somebody else to do it for you.''
The fact that the Liberal Party called for the removal ''forthwith'' of cruise missiles is likely to strain relationships with their allies, the Social Democrats (SDP), who are strongly opposed to unilateralism.
SDP stalwarts like current party leader David Owen and former party president Roy Jenkins have no desire to hear an echo within their new alliance of the unilateralist sentiments they had hoped to leave behind in the Labour Party.
And while the British public has considerable misgivings about the deployment of cruise missiles at Greenham Common, that opposition cannot be interpreted as reflecting deep-seated unilateralism.
A major contributing factor in Labour's crushing defeat at the hands of the Tories in the 1983 general election was Labour's unilateralist policies.
Msgr. Bruce Kent of the CND believes the Falklands war and the patriotism it aroused reduce the public perception of the disarmament movement to a ''minority prejudice.''
Although right-wingers in the Labour Party like former Cabinet ministers Denis Healey and Peter Shore believe unilateral disarmament is naive and unrealistic, Labour is almost certain to appprove the policy when it meets in Blackpool next week for its party conference.
Such a policy goes well beyond the Liberal Party's call for removing unilaterally only cruise missiles from Britain. Labour also wants all nuclear weapons and all foreign bases - that means American - out of Britain as well. Its nonnuclear strategy is considered by some defense experts to be so incompatible with NATO aims as to be unworkable.
Yet even within the Conservative Party, which meets in Brighton the week after the Labour conference, the defense debate is likely to ruffle some feathers. The controversial aspect here is Trident.
The Conservative Party is the only party behind Trident since Labourites, Liberals, and Social Democrats all want to see it canceled.
But among some Conservatives there is a move to reconsider Trident. One potential liability is its tremendous costs. Back in March this year its projected cost was put at (STR)8.7 billion ($10.7 billion). Now with the dramatic drop in the pound's value against the dollar, estimates about its eventual bill have gone up as much as several billion pounds to (STR)12 billion ($14.8 billion).
Conservative members of Parliament are concerned that the much higher cost will be used as an argument against them that the government is placing too high a priority on defense expenditure.