Barely 30 families live on the narrow sliver of sand known as Tuzla Island, fewer when the weather gets bad, or the fishing gets good. The only other landmarks on the half-mile-wide, 4-mile-long sand spit between Russia and Ukraine are two aging, Soviet-era vacation spas, empty except for occasional visits by port workers from the mainland.
The issue of who owns Tuzla Island has been a matter of extreme inconsequence for as long as anyone can remember. When Ukraine and Russia were adjoining republics in the Soviet Union, it hardly mattered. When Ukraine declared independence more than a decade ago, it faced no serious argument from Russia when it penciled its national boundary around Tuzla and began administering the narrow shipping strait nearby that links the Black Sea with the Sea of Azov.
In September, without warning, Ukrainian border guards spotted caravans of dump trucks on the Russian side of the Kerch Strait, which ranges from a width of 2 miles in the north to 9 miles at the Black Sea. Workers were rapidly emptying earth into the water, as many as 180 loads an hour. A causeway began to take shape. And it soon became clear it was headed for ... Tuzla.
"Nothing was being explained to us, what they were building, why they were building it. The Russians were approaching our territory fast, and we had to make a response," Col. Anatoly Samarchenko of the Ukrainian Border Guards said.
The situation rushed downhill from there. The border guards established an outpost on Tuzla and threatened to destroy the Russians' handiwork once it reached Ukrainian territory. The chief of the Russian presidential administration responded that "dropping a bomb" might help resolve the issue. Ukrainian nationalists pledged to muster 27,000 citizen militiamen to defend the island, and on the Russian side, uniformed Cossacks strode defiantly onto the dam.
If almost no one had previously heard of Tuzla, that hardly stopped them from drawing a line in its sand. When a radio station in Moscow asked its listeners which was more important, neighborly relations with Ukraine or Tuzla Island, 82% of the 3,000 people who called in answered: "Tuzla."
A phone call between Russian President Vladimir V. Putin and Ukrainian President Leonid D. Kuchma defused the crisis, halting construction of the nearly 2-mile causeway, just 102 yards short of Ukrainian territory. Last week, the two sides agreed to negotiate the real bones of contention: the Kerch Strait, which flows on either side of Tuzla Island, and more importantly, the adjoining Sea of Azov -- a strategic gateway to the Black Sea and a possible new oil frontier.
In a nation that has been a troubled but usually reliable partner in Russia's shrinking sphere of influence, the dispute has opened a well of mistrust that may not be easily capped.
Since independence, Ukraine's political fulcrum has turned on whether its interests lie eastward, with Russia, or westward, with the United States and Europe. The balance appears now to have tipped. Parliament members across the political spectrum united in a resolution condemning Russia's actions as "hostile," and there are widespread calls for speeding up Ukraine's drive for membership in the European Union and the North Atlantic Treaty Organization.
As Kuchma warned, Russia's attempt to solidify its hold on the former Soviet republic may have produced just the opposite effect. "The closer the dam gets to Ukraine," he said, "the closer Ukraine gets to the West."
Nationalist politicians have had a field day with the Tuzla issue, spoiling for the confrontation that never happened during Ukraine's peaceful exit from the Soviet Union in 1991.
"Tuzla is a reference point, a moment of truth for Ukraine. Relations with Russia will be referred to as 'before Tuzla' and 'after Tuzla,' " Andrei Shkil, a member of the Ukrainian parliament and head of the nationalist UNA-UNSO organization, said in an interview.
"Russia's behavior in the Kerch Strait has sown the seeds of distrust and apprehension in the hearts of even the most ardent advocates of a further rapport between Moscow and Kiev," he said. "The matter at hand is whether Ukraine remains Russia's junior brother forever -- always badgered and insulted -- or becomes an equal partner with Russia."
Here in Kerch, where 80% of the residents are ethnic Russians and hundreds of residents board a ferry every day to go to jobs or visit friends or family on the Russian side of the strait, the dispute is seen as unnecessarily hostile.
Many ethnic Russians, still unhappy that the heavily Russian Crimean Peninsula went to Ukraine in 1991, see in the dam dispute the possibility of reviving plans for greater autonomy.
"What the situation may result in is the residents of Crimea will demand a referendum that will invalidate the decision ... when Crimea was handed over to Ukraine," said Mikhail Shebanov, leader of the Russian Community of Kerch, who said citizens on the Russian side of the strait are living in substantially better economic conditions than those in Kerch, a former industrial town that saw many jobs disappear when trade links to Russia were severed with the Soviet breakup.
The breakup was accompanied by a multitude of ethnic and border disputes, some of which broke out in open warfare, some of which have simmered in quiet hostility for years. The Kerch Strait was one of many simply left to be sorted out. Russia has allowed Ukraine to administer the shipping strait west of Tuzla, without agreeing to Ukraine's claim that the strait is within its national waters.
Exactly why Russia started building the causeway is unclear. Officials in the Krasnodar region, on the Russian side of the strait, said they were simply restoring the land connection that existed before storms washed it away in 1925, to protect coastal residents from seasonal flooding.
While flooding has indeed been a problem, hardly anyone here doubts that Russia's real motivation was control of the strait and the Sea of Azov -- a crucial waterway where a company linked to Kuchma's family has recently been prospecting for oil.
Some Ukrainian analysts ascribe to Moscow even more devious motives, suggesting that instigation of a territorial dispute could automatically delay Ukraine's entry into NATO -- particularly since Russia may see, with NATO membership, the remote but unpleasant possibility that NATO ships could one day sail through Kerch Strait into the Sea of Azov.
The timing, they say, is everything. Kuchma's relations with the U.S. and Europe have been hurt by revelations that in 2000 the president allegedly ordered his minister of interior to take action against independent journalist Georgi Gongadze, who was later found dead.
The situation worsened in 2002, when the U.S. learned that Kuchma allegedly had ordered the sale of Kolchuga aircraft tracking radar to Iraq, in violation of U.N. sanctions.
Faced with criticism abroad and a domestic popularity rating hovering near 7%, Kuchma has tried hard to enlist friends on both sides of his borders. To appease the U.S., Ukraine earlier this year dispatched a nuclear, chemical and biological protection battalion to Kuwait and a peacekeeping force to Iraq. The nation has been working to implement an ambitious and costly democratic, economic and military reform agenda that is a prerequisite to any future bid for membership in the EU or NATO.
A big part of that agenda undoubtedly spells Kuchma's own political demise: The West has demanded free presidential elections next year in which Kuchma, limited by the constitution from running again, will presumably not be a candidate. Yet the president and his lieutenants undoubtedly fear potential prosecution on corruption charges should they lose power to the opposition.
Russia made its first move earlier this year with a proposal to send Russian oil through a new Ukrainian pipeline at Odessa, a plan that would supplant a U.S. oil company's bid to transport Caspian Sea oil to Europe. Then, Putin convinced Kuchma to sign a controversial free trade agreement that critics fear could allow Russia to dominate Ukraine's economy.
Putin has emphasized that the Sea of Azov and the Black Sea are strategically crucial to Russia, providing "direct access to the most important global transport routes."
Kirill Frolov, a Moscow-based analyst, said Russia has never accepted that a vital shipping link should be subject to control by another nation, especially with Ukraine charging substantial fees for its maintenance.
In Kerch, there is a sense of wounded friendship. "I can understand that Russia is a different country, and they do what they want on their own territory," said Olga Arkhipenko, head of the city's domestic policies department. "But from a human point of view, I don't see how they could have started building that dam without warning their neighbors."
Alexei V. Kuznetsov of The Times' Moscow Bureau contributed to this report.