Rapid communication has been essential on the battlefield for as long as humans have waged war. From the legendary roughly 25-mile messenger's run that announced an Athenian victory at Marathon, through war drums, carrier pigeons, and the telegraph, to today's militaries' reliance on high-speed digital links, rapid information transmission is imperative for military success. The speed of a weapons system is essential, too. That is why a sudden loss of satellite connectivity for Ukrainian drones and vehicles moving faster than 100 miles per hour earlier this month represented a major blow to the country's fight against Russia.

A Speed Cap, Without Warning

Overnight from Oct. 13 to Oct. 14, Ukrainian military users found that satellite-connected hardware traveling faster than 100 mph (160 km/h) lost its connection, according to Serhii “Flash” Beskrestnov, a defense technology advisor to Ukraine's president. Some units even reported problems at lower speeds: Ukraine's 7th Rapid Response Corps said connections dropped for 10 to 20 seconds at 110 to 120 km/h, and Ukrainian activist Serhii Sternenko, citing military reports, claimed drops at speeds as low as 60 to 70 km/h—roughly 37 to 43 mph.

Beskrestnov said the restriction applied to Starshield's military service package, the government- and defense-focused version of the satellite internet network run by Elon Musk's SpaceX. (SpaceX's civilian service, Starlink, has more than 12 million customers.) Exactly which service Ukraine's forces rely on has itself become a point of dispute: Secretary of State Marco Rubio said over the weekend that Ukraine does not currently have access to Starshield and that its request for it is “under conversation.”

Whatever the label, the effect on the battlefield was immediate. Ukraine uses domestically built interceptor drones to hunt Russia's jet-powered Shahed attack drones, known in Russia as the Geran-3, which can fly as fast as 370 km/h, or about 230 mph. An interceptor that loses its link above 100 mph—or, by some accounts, above 43 mph—is badly outmatched. Ukrainian sources have said terminals need to work at speeds of at least 450 km/h to counter the jet drones—a threshold above even the Geran-3's top speed.

“The maximum speed today is 161 km/h; after exceeding it, Starlink shuts down, and we lose the drone,” Ukrainian President Volodymyr Zelensky said on Oct. 17, adding that Ukrainian specialists had tested terminals at 180 km/h inside the European Union without losing connection. “The restrictions operate on the territory of Ukraine and do not operate on the territory of EU countries.” Ukraine's Defense Ministry said service had partially stabilized for terminals moving below about 160 km/h, but as of the weekend, Zelensky said the cap remained in place.

Victoria Samson, chief director of space security and stability at the Secure World Foundation, told Fortune in an interview that the interference hurt Ukraine's ability to defend itself, not just its offensive capabilities. It greatly hindered “Ukraine's ability to defend against very high-speed drones,” she said. That happened the same time Ukraine stopped getting early-warning notifications from the U.S. about incoming Russian missiles. “Those things going hand in hand, it seems like there was a deliberate effort to try and impede Ukraine's ability to defend itself,” Samson said.

Outrage at Musk—and on Capitol Hill

Much of the initial blame fell on Musk and SpaceX. Radosław Sikorski, Poland's foreign minister, posted on X: “Hey, @elonmusk, big man, are you playing politics with your products again? As your European customers, we are watching you.” Poland has paid for tens of thousands of the terminals Ukraine uses. (The two men have clashed before: In 2025, Musk told Sikorski to “be quiet, small man” in a dispute over Starlink in Ukraine.)

Condemnation also came from both sides of the U.S. political aisle. Sen. Thom Tillis (R-N.C.) asked Musk on X to confirm the “overnight disruptions to Starlink terminals in Ukraine were unintended” and to clarify SpaceX's position, warning that “intentionally degrading Ukraine's ability to defend itself might be construed as aiding and abetting a mass murderer.” He later called for a Pentagon inspector general investigation. Sen. Jeanne Shaheen (D-N.H.) wrote that “these restrictions on Ukraine's access to Starshield must stop immediately.” (Fortune reached out to both senators' offices for comment but did not hear back before publication.)

Musk Points to the White House

Musk disavowed responsibility, posting on X, which he owns: “Starshield systems are owned and controlled by the US government. Any limits on speed or usage are decided by the US military and ultimately POTUS.”

Two U.S. officials and a Western official later told Reuters that the order to slow Starshield service for Ukraine came from inside the White House, though they did not say who made the decision. A senior Ukrainian official told the news agency that Kyiv had called the White House, State Department, and Pentagon and was told it was a White House decision. Separately, the Telegraph, citing four sources, reported that Musk himself proposed the caps to Trump, who approved them.

Appearing on NBC's Meet the Press on Oct. 18, Zelensky said Ukraine's generals, its government, and he himself believe the throttling was “a message from [the] American government to limit the speed.” He added: “Technically, SpaceX did it,” but “it's limited because it's a decision,” and said service would be restored “if President Trump will decide tomorrow—or better, today—if he will personally decide to lift this decision,” according to Yahoo Finance.

The Trump administration denies any involvement. Rubio, who serves as both secretary of state and national security advisor, told reporters that “no one at the White House ordered anyone to slow down internet or slow down speed so that certain drones couldn't use it,” calling such reports “categorically false,” according to Al Jazeera. He also said the slowdown “sort of happened” but that service had been restored to where it was before—a claim Kyiv disputes. Trump himself told reporters, “It wasn't me, and I don't think it was Elon,” per CBS News.

A String of Moves That Favor Moscow

The throttling comes amid a series of administration moves that have eased pressure on Russia as Trump pushes Kyiv to halt drone strikes on Russian oil refineries, which he has blamed for rising energy prices ahead of the midterms. On Oct. 9, after Trump announced a diesel deal with President Vladimir Putin, the Treasury Department issued General License 135, allowing the sale and import of Russian-origin diesel—blocked by sanctions since 2022, the year Russia launched its full-scale invasion of Ukraine—through April 7, 2027. The deal drew bipartisan backlash in Congress.

Then, late on Oct. 16, Trump signed an executive order waiving nearly all of the substantive sanctions, tariffs, and restrictions in the Lindsey O. Graham Sanctioning Russia and Iran Act of 2026—a law he signed just a month earlier—before they took effect on Oct. 18. The administration has also threatened to cut arms supplies to Ukraine, and Trump has called for Ukraine to get a new president.

A White House spokeswoman has said the sanctions authorities give the president tools to pursue peace. But critics argue that renewed fuel sales and suspended sanctions tariffs put more money in Vladimir Putin's pocket to fund the war.

Several open questions will shape what happens next. Ukraine's Defense Ministry says service has partially stabilized for terminals below roughly 160 km/h, while Zelensky maintains the cap is still in force. Whether the Pentagon inspector general review that Tillis has requested materializes remains to be seen, and Rubio has framed Ukraine's request for Starshield access as “under conversation.” For Kyiv, restoration comes down to a single decision—whether, as Zelensky put it, Trump will “personally decide to lift this decision.”

Those economic measures may weaken Ukraine's position over months. Losing the ability to fly fast drones, by contrast, hurts Ukraine right now—and hands Russia an immediate advantage in the skies.