The Wall Street Journal reports:

NATO said that a series of leaks on the Nord Stream pipelines between Russia and Europe were the result of sabotage and that attacks on its members’ infrastructure would be met with a collective response from the military alliance.

The statement, from the North Atlantic Council, the decision-making body of the North Atlantic Treaty Organization, didn’t provide details or evidence. It also noted that the damage to the pipelines occurred in international waters. But it marks the first time the alliance has formally warned that it would deter and defend against attacks on its members’ critical infrastructure following the now four documented leaks in the Nord Stream and Nord Stream 2 pipelines.

NATO Secretary-General Jens Stoltenberg separately wrote on Twitter that the sabotage on the pipelines was of “deep concern.”

“NATO is committed to deter and defend against hybrid attacks,” he wrote. “Any deliberate attack against Allies’ critical infrastructure would be met with a united and determined response.”

At a NATO meeting Wednesday evening, Danish officials said the pipelines were damaged by several explosions Monday with the force of 500 kilograms of TNT (about 1,100 pounds), officials familiar with the discussions said.

Swedish and Danish authorities said Thursday that a total of four leaks—two in the waters of each country—had been verified. The Swedish Coast Guard said the fourth leak—the second in Swedish waters-—was discovered earlier this week around the same time as the first. The second leak is smaller, and emissions from that leak are weakening, according to the agency’s ongoing surveillance of the site.

The aftermath of the leaks threatens to expand the theater of the conflict in Ukraine, which so far has mostly been confined to Ukraine’s borders, and to conflate it with the economic war playing out between Russia and the West. While the incidents don’t affect Europe’s gas supply—the pipelines aren’t now in use—they have raised fears about the security of the continent’s energy systems as governments work to build up their gas supplies for the winter. [Continue reading…]