Close your eyes and think of the Caribbean. Picture-postcard Caribbean, with wavy palm trees and coco shells on secluded sands, and a turquoise sea. It's not paradise, but in some parts of Vieques you get fairly close.
"You must go to Vieques," advises Morgan, an earnest, pony-tailed psychologist, within hours of my arrival in Puerto Rico. "It is one of our most beautiful islands. You must go and tell the world what is happening there."
By now, the entire world knows what is happening in Vieques: there have been huge protests against the US military based on the island, followed by mass arrests.
The world's superpower has a battle on its hands - a battle that has turned US citizens against their own navy. It is a fight, say the expats, over rum punch and pina coladas, which has all the makings of a showdown between David and Goliath. And that is before Agent Orange and depleted uranium have entered the conversation.
For while this subtropical isle, east of Puerto Rico, is as seductive as any of the Spanish Virgin Islands, large parts of it are in fact firmly out of bounds. It is true that, on tourist maps, each end of the island is marked with the words "Danger: Restricted Area" and with the unmistakable icon of a falling, finned bomb. However, before all the troubles, "you could use the spectacular beaches on both of the US bases" - so says a man who goes by the name of Long John in what is not, I keep telling myself, a bizarre Hollywood script. "Now it looks bad. Some people wanna get hurt. We could have blood here, real blood, like."
It is not hard to see why the 9,000 or so people who live on Vieques are distressed. The island's populated areas remain remarkably untainted by fast-food joints, high-rise buildings and motorways. But 60 years of bombing by the US navy have wreaked havoc on its eastern tip. It is a veritable wasteland, groan environmentalists. Gaping gashes that were once shores, slopes and lagoons now ooze the toxic remains of fragmented missiles and unexploded shells.
"It resembles a battlefield from the First World War, where the ground and a great part of the vegetation has been reduced to dust," says Rafael Cruz Perez, a chemical engineer who once served as an artillery officer in the US army.
But as the US navy sees things, Vieques is simply unique. Two-thirds of the island is under its control, and this holiday destination is now the last place on earth where US marines can combine three-dimensional warfare - aerial bombardment, off-shore gunnery practice and amphibious attacks. Since the 1940s, Washington has pumped about $3bn worth of infrastructure into the island, erecting the Atlantic Fleet Weapons Training Facility.
As one naval officer puts it: "Vieques . . . is absolutely vital to our national security." Indeed, the island served as a rehearsal zone during the Korean, Vietnam, Gulf and Kosovo wars. Nato - in the form of British, Dutch and French warships - frequently joined the practice runs. Vieques was also used as a staging ground for the invasion of Grenada in 1983.
The US navy's strategic interest in the region dates back to when the Puerto Rican archipelago was part of the spoils of the 1898 Spanish-American war. But now, it seems, the locals have had enough. Recent studies show that cancer rates are 27 per cent higher on the island than they are in Puerto Rico, which lies around eight miles to the west. Cardiovascular disease among children is also on the rise. Tourism is down. Unemployment is soaring - the result of the marines buying all the sugar plantations to set up the base. And as if that were not enough, the navy has been forced to admit that it "accidentally" fired 263 depleted uranium-tipped bullets, in violation of federal rules, on a training range near a civilian area. Other lethal chemicals, including Agent Orange, have also been unloaded on to the island by naval pilots over the years.
"More explosives and experimental weapons have been dumped on Vieques from jets, ships, tanks, you name it, than the accumulated amount used in all of the wars in which the US has participated," booms Robert Rabin, the island's self-appointed crusader.
"What we are about to see is a new, intense round of struggle. The navy doesn't understand that, when it resumes manoeuvres that nobody wants later this month, the answer is going to be mass civil disobedience."
If sleepy Vieques is among the more improbable settings for a native uprising, then Rabin, a former Bostonian high-school teacher, makes for an equally unlikely revolutionary. Rabin leads the unexpected cast of characters who now appear bent on challenging US power. And what's more, he is deadly serious.
"This time round is not like before: there is overwhelming consensus on the matter," he tells me, ensconced in the island's fort museum cum operational base, where he is the resident director of cultural events. "Now that the cold war is over, the navy can't go round saying that we're Russian, Cuban and Chinese spies who only want to disrupt life in America. People don't buy that any more. They have seen for themselves what the bombing means and they don't want it."
Called "Che" by his admirers, Rabin has been able to draw from a groundswell of support since two errant 500lb bombs killed a civilian security guard on the grounds of the navy's Camp Garcia, two years ago. The killing prompted protesters to stage a year-long sit-in at the installation. Pacifists and adventure junkies came a-flocking from across the US. Last November, Puerto Ricans elected a new governor who ran on an anti-navy platform.
"You always know when the navy is getting nervous because it resorts to its bag of dirty tricks," Rabin growls. "There's a lot of psychological warfare going on, nasty telephone calls, poison-pen letters . . . Vieques is crawling with special forces operatives and agents from the FBI."
The navy has initiated an unprecedented public relations campaign. Glossy pamphlets have rolled off the presses, extolling its ecological record on the island, starting with a sea-turtle conservation project that has seen thousands of hatchlings being released into the wild. Airtime has been bought on local radio and TV.
The navy is not alone in clearly loathing "Che". Down at Al's, a favourite watering hole for gringos who happen to be former military men, Rabin is brushed off, curtly, as "that well-known Marxist".
"Rabin just hasn't understood that it all boils down to money," says Long John. "Only a small part of the base, the target range, has been destroyed. What these people want is to kick the navy out and build a Club Med and other big hotels instead."
But it is the reawakening of Puerto Rico's Independence Party - and the political capital it has made out of the imbroglio - that suggests the superpower is up against something bigger.
The Independistas are a proud and fierce lot: men and women who view themselves as an integral part of the Latin American family of nations. And they have made no bones about how they see the navy's eviction from Vieques as a prelude to ridding Puerto Rico of the US armed forces, federal courts and its murky status as a colonial commonwealth. Half of the island's inhabitants may survive on American food rations and social security benefits but, according to Ruben Berrios, the Oxford-educated leader of the Independistas, Puerto Rico still has "a basic problem". "And that is the dependence and subordination inherent in colonialism, not only legal and political, but also economic, cultural, social and psychological," he says. "Independence would release the full spiritual energies of a nationality whose self-esteem has been trampled on."
For many, the US sealed its formal occupation of Puerto Rico - so necessary in extending its influence over Latin America - by granting islanders US citizenship in 1917. But while Puerto Ricans remain exempt from federal income tax, they cannot vote in presidential elections and have little more than observer status in Congress. The emergence of superstars such as Ricky Martin has not stopped the flow of complaints that they are treated as "second-class citizens" by their compatriots.
For the protectorate's three political parties - each defined in terms of its stance on the island's political status - Vieques now poses a huge turning point in US-Puerto Rican relations.
"Vieques has become a rallying point for other causes because it is a symptom of Puerto Rico's unresolved issue of democracy," points out Pedro Rosello, a former governor of Puerto Rico. "When you have four million citizens who are basically disenfranchised, you will have symptoms like these."
Part of the problem, too, is that Puerto Ricans have never been united over their future. Indeed, in repeated referenda they have always elected to keep the status quo. "There's no doubt Puerto Ricans vote with their pocketbooks and not with their hearts," says Professor John Coatsworth, Harvard University's pre-eminent specialist on Latin American affairs. "If they were free to do so, they would vote for independence or a kind of autonomy that is certainly more than what they have at present."
For "Che" Rabin and his rag-tag army, things are looking up. So far, the new powers that be on Puerto Rico are backing the insurgents. The Dalai Lama has wished them well. The Green Party has brought the case before the Dutch parliament, and agitators against other US bases - from Japan to Britain, Hawaii to the Philippines - have taken up the cause.
With the US navy digging in, resuming exercises for the first time since 1999, a heady sense of optimism fills the otherwise picture-postcard atmosphere of Vieques.
"The whole point is that we get arrested," declares "Che" Rabin, his eyes sparkling. "This becomes a huge, unstoppable, full-scale civil disobedience act. We don't care what we have to come up against; it can be federal marshals, marines, the coastguard or even forces from the inter-planetary police."
While the revolutionaries cannot count on this, they believe that, one way or another, suffering will bring them closer to the Caribbean paradise they so dearly want.
Helena Smith is a Nieman fellow at Harvard University