Some analysts warn of a "ring of fire" threatening stability from Indonesia to the eastern Pacific, posing tough questions for the region's cornerstone democracies, Australia and New Zealand.
The issues include the diplomatic and economic risks of getting involved and the limited capabilities of our defence forces.
Associate Professor Steve Hoadley, of the Auckland University political studies unit, says Pacific instability is a wakeup call to those who believe New Zealand is immune from external threats.
It highlights our potential obligation to support Australia in any conflict on its doorstep, and our need to have the full range of military capability - Army, Navy and Air Force. He believes New Zealand needs to prepare a "menu" of responses to any situation, including diplomacy, economic sanctions and military backup.
The ring of fire, or arc of insecurity, starts with Indonesia, plagued by growing separatist protests and religious violence.
This vast and ethnically diverse archipelago, united only by opposition to Dutch colonial rule and racked by wealth disparities, is in danger of breaking apart. The clamour for independence ranges from Aceh and Riau in the west to Irian Jaya (West Papua) in the east, while religious violence ravages the Moluccas (the former Spice Islands).
On Sunday, the indigenous people of Irian Jaya announced plans to break with Indonesian rule and form a new Papuan government. Jakarta's exploitation of the province's natural resources and neglect of social welfare are blamed for the rising secessionist mood in Irian Jaya.
Over the border, Papua New Guinea is battling financial crisis, social unrest and political scandals as peace talks for the island of Bougainville lurch towards impasse. The PNG Government has offered autonomous rule but continues to resist full independence.
Ethnic conflict in the impoverished Solomon Islands saw 60 people killed in the 18 months before the Queen's Birthday Weekend coup by the Malaitan Eagle Force.
The model for the storming of Prime Minister Bartholomew Ulufa'alu's home on Monday undoubtedly came from George Speight's raid, 17 days earlier, on Fiji's parliamentary compound in Suva.
There, economic frustrations, political divisions among indigenous Fijians and ethnic hatred fuelled the assault on Prime Minister Mahendra Chaudhry's year-old regime and the constitution that helped him to power.
In nations close to our shores, including New Caledonia, Vanuatu, Samoa, Tonga and the Cook Islands, similar sources of discontent exist. They include ethnic rivalry, corruption, economic problems, nationalism and constitutional problems. They vary in intensity and need not escalate into violent uprising - but Fiji and the Solomons have demonstrated to Wellington and Canberra that they might.
Dr Jim Rolfe, defence analyst and lecturer in international relations at Victoria University, says there is a risk that the success of violence in Fiji and the Solomons will legitimise its use elsewhere. But he is reluctant to pinpoint the next likely troublespot.
"Once you start naming countries, there's a danger of a self-fulfilling prophecy. Pretty well every country in the region has internal divisions which, if exacerbated, could lead to some group or another trying to resolve it by force."
Waikato University's head of strategic studies, Dr Ron Smith, says New Zealand and Australia could easily be dragged into conflict in Indonesia and Papua New Guinea if conditions deteriorate.
"There's a lot of sympathy in Papua New Guinea with the Irian Jayans, and it's possible that a border conflict would draw Australia in and they would call for a response from us."
New Zealand's investment in the Bougainville peace talks could also imply an obligation to act if they collapse.
"In all these South Pacific countries there are minorities and ambitious politicians who are learning lessons from Fiji and the Solomons.
"Every time someone like a Rabuka [leader of Fiji's 1987 coups] or a George Speight gets advantage from using violence, everyone takes the message that that's the way to go."
Dr Alley says uprisings in Pacific nations are not surprising, given their economic problems, structural neglect, corruption and unresolved constitutional issues.
He is wary of the appearance in Bougainville, Fiji and the Solomons of "Rambo-style" unemployed youths. "There's a kind of pool of rent-a-mob characters roaming around who never got much out of the system."
He detects a "scary insularity" driving the usurpers. "Somehow you've got to get these people at a certain stage to sit down and talk about it."
But it is a delicate balancing act. New Zealand and Australia risk a backlash if they are seen to be interfering in other countries' domestic affairs.
Dr Alley says we have to find a way, while avoiding accusations of neo-colonialism.
"It's a pretty defeatist view to say, 'We'll just stand on the sidelines and when you people are all war-weary we'll step in with mediation' ... There must be ways of getting involved that are not overtly military."
Dr Smith agrees: "Perhaps New Zealand's main effort should be to identify problems early ... and make the offer to facilitate, as we did in Bougainville."
The potential for widening conflict makes nonsense of restraint on defence spending by successive Governments, he says.
Our presence in East Timor left us with "nothing to offer anyone else. We couldn't contemplate another deployment."
For the Government in Canberra, the Solomons coup has further highlighted Australia's isolation from its near neighbours. Its defence resources are stretched by the deployment of 2500 peacekeepers on East Timor while others are serving on Bougainville.
Australia spends about 1.8 per cent of gross domestic product on defence and remains adamant that New Zealand should allocate at least a similar proportion, instead of the present 1.09 per cent. But, like New Zealand, the Australian Government is contemplating budget cuts which could force it to shed ships, planes or troops - or all three.
Dr Hoadley says the continuing instability on Australia's northern frontier highlights the need for New Zealand to boost its Air Force, Navy and Army.
A preoccupied Australia is also likely to look to New Zealand to show leadership closer to home - keeping an eye on events in New Caledonia, Vanuatu, Samoa and Tonga, he says.
In this part of the Pacific, New Zealand is regarded as a regional power with the capacity to help.
"New Zealand can be supportive, it can bring pressure to bear and it can talk. Other nations will look to New Zealand to set the pace.
"But ultimately, it's over to the local people to act and to do the right thing."
* Additional reporting by Greg Ansley in Canberra.
George Speight talks to IRN's Barry Soper
(10 min).
