The Government of the late Sir Robert Muldoon tried to persuade the United States to mislead New Zealanders on the extent of its commitment to defend the country under the Anzus alliance, confidential Australian papers reveal.
The 1983 Australian Cabinet papers, released by the National Archives, show that Sir Robert was afraid support for the alliance would be undermined if New Zealanders understood the limits Washington had placed on military support.
And while the then Secretary of State, George Shultz, had explained those limits "quite categorically" during talks between alliance ministers, both the US and New Zealand fudged the reality of America's position in the communique the Anzus Council issued.
Two years later, the New Zealand Labour Party's ban on nuclear ship visits and New Zealand's subsequent suspension from Anzus settled the issue and ended any treaty obligation for the US to respond to an attack on the country.
Australia, which remained then, as now, a staunch supporter of the alliance despite concerns for its independence in foreign affairs, was under no illusions.
A submission to the Cabinet by Foreign Minister Bill Hayden said America's limited commitment had been made clear in both the wording of the 1952 treaty and by former President Richard Nixon's 1969 Guam doctrine. This said that while the US would fulfil all treaty commitments and defend an ally threatened by a nuclear power, and supply military and economic assistance during other acts of aggression, it expected allies to provide for their own defence.
But the submission, reporting on the July 1983 Anzus Council meeting in Washington, said New Zealand wanted to present a different picture because of its limited resources and to avoid giving its public the impression of any weakening of the value that successive National Party governments had placed on the alliance.
"The New Zealand side was, not unexpectedly, reluctant to engage in any constructive recognition of the implications of greater regional self-reliance obligations arising from the so-called Guam doctrine," the submission said. "Above and beyond that there is no doubt that the New Zealanders' attitude was very much conditioned by domestic political considerations.
"It is quite obvious that they are hoping to get the New Zealand Labor Opposition wrong-footed by presenting Anzus as a firm and unwavering guarantee of military commitment by other members in all threat/attack circumstances. Anzus is not such a guarantee."
In the submission, Mr Hayden said it was clear a great deal of overnight pressure had been applied to the Americans by New Zealand in an attempt to convince them to haul back from Mr Shultz's statements on the first day of the council, when he said that all Anzus guaranteed in the event a threat against, or an attack on, a member country was a "response" from the other members.
Mr Hayden said Mr Shultz had said "quite unambiguously" that the response would not necessarily be military and that there were a range of alternatives. Mr Shultz had also emphasised that any response would be in accordance with the constitutional processes of member states.
"As a consequence of this New Zealand sensitivity, both the US and New Zealand were reluctant to spell out in detail in the communique that there could be a range of responses other than direct military support in the event of an attack or threat," Mr Hayden's submission said. Australia and New Zealand could expect the US to "assist" in circumstances of a great power conflict, but that this could not be taken for granted in a lesser contingency involving the use of force.
Mr Hayden said the Guam doctrine was "eminently sensible" in expecting treaty members to maintain a decent level of defence capacity able to operate on its own in small-scale emergencies.
But he said Australia had been surprised by America's challenge to this view.