QAMISHLI, Syria — A boycott of Turkish goods by Syrian Kurds was intended to express Kurdish anger at Turkey’s assault against their autonomous enclave — but it has also revealed the extent of the Kurds’ dependence on their bitterest foe.

The expansion of Kurdish control in northeastern Syria over the past seven years, helped by U.S. military assistance in the war against the Islamic State, exacerbated animosities between Turkey and the Kurds.

Yet even as the Kurds asserted their autonomy, their reliance on Turkey grew. As the wider Syrian war devastated Syrian industry and severed traditional trade routes, Turkish goods flooded into the area, mostly via Iraq, across a wobbly pontoon bridge on the Tigris River, which now serves as the Kurdish region’s only outlet to the outside world.

Today, more than 80 percent of northeastern Syria’s imports are from Turkey, said Salman Baroudi, the region’s senior official in charge of agricultural and economic policy.

Since Turkey invaded a portion of the Kurdish enclave in October — encouraged by President Trump’s withdrawal of U.S. troops from the area — a boycott of Turkish products promoted by the self-styled administration has proved difficult to enforce.

“Turkey is attacking us, shelling us and killing our children, so how can I buy their goods?” said a mother who asked to be identified by her nickname, Umm Ali, as she shopped for groceries in a Qamishli store. However, she said, some essential items such as cooking oil and tomato paste simply cannot be sourced without buying products imported from Turkey.

“I only buy Turkish products if there is no alternative,” she said.

The grocer, Jawan Sheikhmous, said his customers welcomed alternatives, but they are hard to come by and expensive. Turkish apples, for example, cost half as much as Syrian ones because the Syrian government imposes high taxes on products entering the Kurdish areas through wartime checkpoints erected along the country’s highways, he said.

Meanwhile, big merchants have been scoring profits by withholding stocks of Turkish products they bought before the incursion, jacking up prices and hurting consumers, said Abdul-Bassil Shafiq, a liquor merchant. He cited the example of Efes beer, which dominates the relatively small market for alcohol and for which no Syrian alternative is available. The price of a beer has gone up more than 25 percent since the Turkish incursion, he said.

“The ordinary people are the victims of the policy,” he said. “Syrian goods would be preferable, but they don’t exist.”

Most of the recent price increases are due to a sharp fall in the value of the local currency, the Syrian pound, and not to price-gouging by merchants, said Jinda Ali, who oversees economic policy for the Qamishli local council. The administration realizes it can’t force people to observe the boycott but hopes to use the opportunity to promote local industry, she said.

Some items have fallen out of Syrian production altogether. There was a time when Syria exported underwear to the entire Middle East, including Turkey, said Kamiran Sinjo, who has an underwear store in the traditional Qamishli souk, or bazaar. Years ago, he manufactured his own line, mostly pajamas and thermals, until war intervened to make it hard to source materials and market his products.

“We were swamped by Turkish goods,” he said. “Now we’re thinking of starting again.”

Khabat Abbas in Qamishli contributed to this report.