Sergey Rylov heard the thud as a Russian missile was shot down on its way toward Bilhorod-Dnistrovskyi, a town on the Black Sea coast of Ukraine where he’s lived since fleeing the fighting in the east a month ago.

His immediate thought was that he’d be keeping his daughter home from kindergarten that day. His second? “The war’s coming here too.”

The attempted missile strike last Friday was still a rarity compared to the now-familiar routine elsewhere in Ukraine since Russia invaded on Feb. 24. But until recently, the southwestern-most corner of Ukraine that curls between Moldova and Romania had been largely untouched by the war, providing a transit corridor for cargoes no longer able to use sea ports that once handled 70% of Ukraine’s trade.

Odesa, just 50 km (31 miles) away and the region’s administrative capital, has been less fortunate. On Monday it was again hit by multiple missile strikes. Mariupol, further east, lies in ruins.

But as the invasion settles into a war of attrition, with logistics playing a decisive role, this ethnically mixed and traditionally pro-Russian region known locally as Bessarabia is growing in strategic importance.

Fears have risen since April 27, when missiles twice struck the crossing at Zatoka, which carries the only road and rail connection between Bessarabia and the rest of Ukraine.

It wasn’t clear whether Friday’s missile attack was a further attempt to destroy the steel bridge, about 20 km from where Rylov stood holding his daughter’s hand at the water’s edge. Journalists were turned away at a checkpoint 12 km away.

On a recent day, the road west toward the border with European Union member Romania was clogged with grain, fuel and container trucks. A line of mostly 18-wheelers waiting to cross into Romania and its busy Black Sea port at Constanta stretched for about 3.5 km.

With Russia’s blockade of sea ports around Odesa forcing trade to reroute, cargo volumes through Ukraine’s smaller Danube river ports have quadrupled since the start of the war, to 850,000 metric tons in April, according to Ukraine’s infrastructure ministry.

The ministry says it aims to boost that to 1 million metric tons per month, and increase rail freight capacity to the EU. Russia may have other plans.

“Exploding the bridge was primarily an attempt to cause serious economic damage to the area and disrupt logistics,” said Alexander Kovalenko, an Odesa-based analyst who writes on defense for the website Inforesist.

Trucks now have to drive through Moldova to get from one part of Ukraine to the other, or to and from the Romanian border. That road crosses a second bridge, whose destruction would complete the region’s isolation from the rest of Ukraine.

Some trains were still towing grain cars along the track that runs from Zatoka on the weekend, suggesting the bridge may not be completely destroyed. On Tuesday, the bridge was again hit by a missile strike.

Shortly before the war, Kovalenko was among defense analysts who said they saw the bridge’s destruction as a key risk to Odesa, because it might enable Russia’s Black Sea Fleet to make an unopposed amphibious landing on the sandy beaches of Bessarabia, with Ukrainian defense forces unable to reach them.

From there, Moscow’s troops could move the short distance to Moldova’s pro-Russian separatist territory of Transnistria, joining with the Russian garrison stationed there alongside local military to turn south and threaten Odesa.

The loss of the main road through Zatoka remains a concern for the government of Moldova. It sees a risk of being drawn into the war if perceived by either side as allowing the 8 km stretch of road that’s now the sole connection between two parts of Ukraine to be used for military purposes, according to an official who asked not to be named due to the sensitivity of the matter.

But it’s a sign of just how badly the invasion has gone for Moscow that — while not discounted — an amphibious landing to secure or destabilize Bessarabia may at this point be beyond Russian capabilities.

“If they make such a landing attempt, it will be suicidal for them,” says Kovalenko. Not only have local defenses been built up nearly three months into the war, but the fleet’s amphibious capacity in the Black Sea has shrunk, following the loss of several landing craft hit by Ukrainian missiles. Russia has also lost its flagship Black Sea warship, the Moskva.

That’s potentially all the more galling for Moscow, because Bessarabia traditionally has been pro-Russian. In 2015 the region saw an — albeit unsuccessful and slightly farcical — attempt to secede from Ukraine when a group of separatists called a press conference at an Odesa restaurant to announce plans for a Bessarabian People’s Republic. Few answered the call and the leaders either disappeared or were arrested.

“The thing to remember is that we have several national groups here,” says Ihor Skorobreha, who organizes volunteer guards against any Russian incursion in Izmail, the region’s largest city on the northern branch of the Danube which forms the border with Romania. Among those are Ukrainians, Bulgarians, Moldovans, Orthodox Christian Turks known as Gagauz and others. Their lingua franca is Russian and ties to Kyiv, he said, have always been weak.

The Bulgarians, Gagauz and more generally the rural poor still tend to be pro-Russian, but not enough to fight for Moscow, should that time come, according to Skorobreha.

“To be honest I thought it would be worse. A lot of people came forward to volunteer for the territorial guard and many I wouldn’t have expected,” he said, speaking on Izmail’s broad central boulevard.

More than 10,000 volunteers from Bessarabia have been trained up to fight, Odesa’s territorial defense unit said in a Facebook post on Tuesday.

In Izmail a statue to Alexander Suvorov, the Russian general who first captured the city from the Ottoman Empire in 1790, has been draped in Ukrainian flags. In a still divided region it was, said Skorobreha, the best way to ensure the monument wasn’t torn down, inciting tensions.

This is the problem writ large for Moscow, says Thomas De Waal, a London-based senior fellow at Carnegie Europe, a think tank, who wrote a report on the Bessarabia region in 2018. “They believed Russian speakers were alienated from Kyiv and would come rushing into the arms of the Russian army. That was a misunderstanding.”

Back in Bilhorod-Dnistrovskyi, restaurant owner Tatyana Shevchenko said many locals have now fled, replaced by refugees such as Rylov, 34, who before the war oversaw the construction of wind farms.

She said the banquet being laid out on a long table, a daily event before the war, was the first to be booked in three weeks. “Before we used to complain about all our problems — that there wasn’t enough money, that the government was no good and all that,” says Shevchenko. “Now we realize we were happy.”