Through the South Caucasus, the Aras River cuts a path through geopolitical friction. At various stretches, it forms the national borders of Turkey, Armenia, Azerbaijan and Iran. All are suspended in various states of tension at this strategic land bridge between Asia and Europe.

Now the river itself risks straining those pressures. In recent years, cross-boundary waterways have grown increasingly controversial the world over. Rising temperatures and booming demographics have exacerbated competition for water, most notably, along the Nile, where proposals for the construction of a hydroelectric dam in Ethiopia have caused a significant rift with downstream nations Egypt and Sudan. In the South Caucasus, however, it is not quantity, but quality that is at stake.

A steel plant, its waste to be dumped in the river, is under construction on the border between Azerbaijan and Armenia. Backed respectively by Turkey and Iran, these neighbors have been locked in a 30-year dispute over Karabakh — a region of Azerbaijan occupied by Armenia since the collapse of the Soviet Union. A short conflict in late 2020 saw Azerbaijan take back control of most of its territory before a cease-fire halted hostilities. Despite recent progress under United States and European Union mediation toward a durable peace settlement, a deal has not been reached. With a litany of entangled grievances and thorny issues between the two nations, cross-border contamination is the last thing negotiators need in what has proved one of the world’s most intractable conflicts to resolve.

In the wake of the Ukraine war, resolution has become more urgent from the West’s perspective — as demonstrated by the uptick in diplomatic efforts to mediate a resolution since last year. Azerbaijani Caspian gas is increasingly important for Europe’s energy diversification from Russian supplies — an endeavor critical to maintaining trans-Atlantic solidarity. Instability throws the supply into doubt. Consider that the narrow path through which the pipelines run to Europe came under fire from Armenia during the 2020 conflict.

At the same time, peace would weaken Moscow in its near abroad. Having brokered the cease-fire, the Kremlin placed 2,000 soldiers as peacekeepers in the region. Currently serving to project Russian power beyond its borders, a settlement would render them redundant. In the wake of Ukraine, Armenia has also sought to break free from Russia — historically its ally in the conflict with Azerbaijan. But in the absence of peace, and given Armenia’s long-ingrained military dependency on the pariah backer, its space for maneuver is restricted. With its sovereignty compromised, the Kremlin can bully Armenia into helping it dodge sanctions — as seemingly borne out in steep increases in Western imports and rising exports to Russia.

Given America’s interest in a resolution, it is ironic that the plant causing new tension is an American-Armenian joint venture. It sits less than half a mile from the border with Nakhchivan — an Azerbaijani exclave separated from the mainland by a roughly 25 mile wide strip of southern Armenia. Given the high likelihood of environmental damage to its territory, Baku’s approval of the plant is required under international law. Armenia is a member of the United Nations Convention on Environmental Impact Assessment in a Transboundary Context that obliges states to consult each other on all major projects that will have a significant adverse cross-border environmental impact. Yet this did not take place.

The plant has also provoked concern from a group of Civil Society Organizations that have signed a collective statement expressing opposition to the project. Nakhchivan is an ecological idyll in the post-Soviet region. The largest landlocked exclave in the world, it has developed in isolation. When the war between Armenia and Azerbaijan began in 1988, the former destroyed the rail and road links within its borders that connected Nakhchivan to the rest of Azerbaijan.

More than three decades of closed borders have ensured its continued seclusion. But it also necessitated a philosophy of self-reliance that has made it one of the most sustainable regions in the world. This pristine area is now directly threatened by the polluting plant. But the waste discharged down the river also raises concerns for flora and fauna, drinking water and irrigation for farms further afield than Nakhchivan — into Armenia, Azerbaijan and Iran before being deposited in the Caspian Sea.

Paired with Armenia’s poor history on mine pollution, which has often provoked protests within the country, it is perhaps unsurprising that the plant has sparked such resistance. In the region that lies at the heart of their conflict, Karabakh, illegal mining has also led to the alleged destruction of more than 17,000 acres of protected forests — including ancient woodland — in a landmark case currently being undertaken by an international arbitration under the Bern convention for nature. Meanwhile, a U.N. Environment Programme report found serious damage to valuable farmland and water-management systems in the territory while under Armenian occupation.

The environment has long been collateral damage in the protracted conflict between Azerbaijan and Armenia. It would be a cruel twist of fate if it now blocked peace.

Ivan Sascha Sheehan is the associate dean of the College of Public Affairs and past executive director of the School of Public and International Affairs at the University of Baltimore. Opinions expressed are his own.