AMNA NAWAZ: A key component of Ukraine's communications network was partially disabled today, perhaps by its ally the United States.

The Starshield satellite network, funded by the Pentagon and operated by Elon Musk's SpaceX, was not operating at full capacity today, hampering communications within the Ukrainian military.

Liz Landers has that story.

LIZ LANDERS: Overnight in Kyiv, homes engulfed in flames, as rescue workers rushed to put out the blaze and save the victims of Russia's latest brutal onslaught, as it continues to target Ukraine's energy infrastructure, plunging the nation's capital into darkness.

This comes just three days after President Trump announced on TRUTH Social a -- quote -- "energy cease-fire" in the war between Russia and Ukraine and that -- quote -- "both parties have agreed."

Since Trump's announcement Sunday, Russia has struck at least 26 energy facilities across Ukraine.

And the war-weary nation feels it is being abandoned by its ally, President Zelenskyy told Piers Morgan today.

VOLODYMYR ZELENSKYY, Ukrainian President: We are a losing strong partner.

So this is my opinion.

And... PIERS MORGAN, FOX Nation Host: You think you're losing America?

VOLODYMYR ZELENSKYY: Yes, but not because of us.

We -- I mean this.

We can't be weak.

Otherwise, we can't survive.

It's painful when President Trump chooses one side, not our side.

But we are OK that he's in the middle.

But if you're in the middle, you have to stay in the middle, not on the wrong side.

I think his advisers are wrong.

I don't know who is pushing him not to the right side.

This is not right side of history.

LIZ LANDERS: As the two allies' relationships shows signs of fraying, Ukraine has accused the United States of not providing advanced warning of the Russian strikes, although the Ukrainian president told NPR it was a -- quote -- "technical glitch," and of temporarily limiting their usage of the Starshield satellite system, a military version of the Starlink network, which is integral to Ukraine's targeting of Russian military installations within Russian-occupied Ukrainian territory.

Starshield's thousands of satellites provide Ukraine with the broadband connection needed to find and target Russian military equipment and personnel across Ukrainian territory, along with data for interceptor drones that take down Russian attacks, that ability severely curtailed, as President Zelenskyy stressed today.

VOLODYMYR ZELENSKYY: It's a big mistake, a lot of losses.

This decision will bring a lot of human losses.

PIERS MORGAN: People are dying because of this decision?

VOLODYMYR ZELENSKYY: Of course.

People will die, of course, if attacks will continue and if Starlink will not work.

Of course, I mean, this -- it's not helpful.

So my message is, absolutely, I hope that it's mistake, maybe huge technical problem.

I don't know.

But we are asking to do it, to switch on.

LIZ LANDERS: Late today, former Defense Minister Mykhailo Fedorov posted on X that Starshield link connectivity is being -- quote -- "restored," to which SpaceX CEO Elon Musk responded on X that -- quote -- "Any limits on speed or usage are decided by the U.S.

military and ultimately POTUS," as Ukraine grapples with a war and an ally it fears it can no longer depend on.

For the "PBS News Hour," I'm Liz Landers.

AMNA NAWAZ: For more on all of this, we turn now to retired rear admiral mark Montgomery, who served on the National Security Council staff, later on the Republican staff of the Senate Armed Services Committee.

He's now a senior fellow at the Foundation for Defense of Democracies.

Admiral, welcome back to the "News Hour."

Let's just start with some context here.

How crucial is this Starshield satellite system to Ukraine's war effort?

What does it allow them to do offensively and defensively?

REAR ADM.

MARK MONTGOMERY (RET.

), Foundation for Defense of Democracies: So the Starshield system, particularly in this, what we're talking about here, which is operating over Russian-occupied Ukrainian territory, is critical to what you call mid-range strike, the ability to hit, say, the logistics lines that flow Russian equipment and supplies into Crimea and the logistics and command-and-control that support their frontline units.

So that mid-range strike is really critical to the military resilience right along the front line where the two forces are engaged.

But you can't understate the criticality of maintaining communications with the mid-range strike drones before they hit their targets.

AMNA NAWAZ: So if those communication systems are limited, if they are throttled, if they are slowed down, what is the practical impact of that on the ground?

You heard President Zelenskyy there say people could die as a result.

Is that true or is that hyperbole?

REAR ADM.

MARK MONTGOMERY (RET.

): Absolutely.

In the case of this, the people are Ukrainian military personnel, because this mid-range strike is really about hit hitting assets to support the Russian military in conducting operations against the Ukrainian corps and task force along that fortress belt.

So they will lose -- if they don't conduct these strikes, they will eventually lose personnel.

AMNA NAWAZ: So it does seem now as if that service, those communications are mostly back up.

You heard President Zelenskyy also say he hopes the limitation there was a mistake or could have been a technical glitch of some kind.

Do we know for sure if there was an intentional decision behind that slowdown or if this could have been a technical issue?

What's more likely here?

REAR ADM.

MARK MONTGOMERY (RET.

): So we don't know for sure yet, and we may not know until we hear on TRUTH Social.

But I think the most likely thing is a strong signaling message from President Trump to President Zelenskyy: Don't complain about my actions with regard to Russian diesel fuel, and don't -- don't strike Russian refineries probably at least through the end of the elections, our midterm elections.

AMNA NAWAZ: And based on what you know about how this company works, how those satellite systems work, would a decision like that have to come from the U.S.

president?

Could it have been made by Elon Musk himself?

REAR ADM.

MARK MONTGOMERY (RET.

): No, I think Starshield is run -- that - - Elon Musk's X statement was true that Starshield's operations on a day-to-day basis are run by the U.S.

military, the U.S.

government.

AMNA NAWAZ: As you mentioned, those Starshield communication systems, they provide data to the Ukrainian drones flying over Ukraine and also over Russian-occupied Crimea.

Do you believe those limitations should be lifted?

Should those communication systems enable further use of Ukrainian drones?

REAR ADM.

MARK MONTGOMERY (RET.

): Absolutely.

I mean, what we're talking about here is those mid-range drones.

Their long-range drones operate over Russian sovereign territory.

It's very reasonable for them to have access to this communications to conduct purely defensive strikes.

And by that, I mean striking Iskander missile launchers, ballistic missile launchers, before they launch.

So you hit the archer, instead of the arrow, or hit stowage sites for ballistic missiles and other offensive Russian weapons.

You know, so that's a reasonable ask of Starshield and Starlink.

And, in fact, prior to this, there was some effort being made by the U.S.

Congress to ask the president to engage Elon Musk on this.

AMNA NAWAZ: If these communication systems were throttled intentionally now, do you believe that could happen again?

REAR ADM.

MARK MONTGOMERY (RET.

): Oh, absolutely.

That's the signal.

The signal is, if Ukraine strikes energy Russian refineries, they can inspect some throttling.

If I were President Zelenskyy, I'd tell my operational planners, hey, do me up a great four-week plan where I strike everything every piece of infrastructure in Russia except refineries.

Vladimir Putin's critical infrastructure is vulnerable in many, many places, not just the refineries.

AMNA NAWAZ: That is retired Rear Admiral Mark Montgomery joining us tonight.

Admiral, always good to speak with you.

Thank you for your time.

REAR ADM.

MARK MONTGOMERY (RET.

): Thank you.