THE PRIME MINISTER OF THE COOK ISLANDS, SIR THOMAS DAVIS, BEGAN 1986 BY DECLARING that he intended to proclaim his country formally neutral. Sir Thomas offered, in explanation, his belief that the ANZUS regional security pact was in collapse, leaving the Cooks solely dependent on a bilateral defence relationship with New Zealand which he described as worthless. Apparently, Sir Thomas wanted to indicate that if his country could not rely on a regional arrangement for its security, he would prefer to fall back upon an ostensibly unilateralist solution (neutrality) buttressed by the global guarantees of international law. Whether or not his declaration was a ploy to embarrass the New Zealand Labour Government of David Lange in its dispute with the United States over nuclear warship port access, and notwithstanding the practical and legal impediments to carrying out his intention, Sir Thomas's gesture epitomizes the dilemma facing the South Pacific regarding regionalism and the security of the region. Many of the underpinnings of the Pacific Islands regional system come from outside the islands themselves, and yet these same supports are linked to sources of danger which threaten not only the validity of the regional system but also the exercise of sovereignty by member states. Regionalism has played a central if contested role in the international affairs of the South Pacific since at least World War II. The small states of the South Pacific are more obliged than most to pursue their international objectives through single rather than multiple avenues. The loss of regionalism as an effective avenue of diplomacy would therefore impose vastly more significant costs on the South Pacific states than would be expected in other regions. This review of regionalism and security focuses on two central themes of the current security debate. The first concerns the nexus between regionalism and regional security: that is, how important is the vitality of the regional system to the security of the South Pacific? Second, to what extent can regional security in this part of the world be independent of the global priorities of the superpowers? The answers to these two questions are not necessarily mutually compatible. Indeed, the prospects for security in this region could depend upon insulating the regional system from many extra-regional pressures, at least under the existing framework. The islands (as well as other states) may find that retaining the South Pacific regional system involves both structural change and a shift away from the traditional, tacit, Western alignment on security issues.