Russian journalist Alexander Sladkov said that Russia's military conducts half of its communications via the messaging app, and said an alternative must be created "urgently."
"Pavel Durov was arrested. This attack on the owner of [Telegram], on which half of the communications in the [war] are held, was expected. Now we urgently need to create a Russian military messenger," he wrote.
"Well, was it impossible to think about this earlier?! Why did the Wagner Group have such a messenger, but the armed forces of our great Russia do not!?!?" Sladkov said, referring to the Russian paramilitary outfit led by the late Yevgeny Prigozhin. "And there is no one to punish. Or maybe we shouldn't look for the guilty? Russia's punishment is carelessness. And this is a nightmare."
Russian military blogger Alexei Sukonkin said Durov's arrest "raises a host of problems that need to be addressed immediately."
"Because: Telegram is currently...the basis of military communications," he wrote. "From now on, all of this is under threat. Isn't this August's main tragedy?"
The Russian Telegram channel Rybar, founded by Mikhail Zvinchuk, a former employee of Russia's Defense Ministry, similarly pointed out that Telegram "has now become almost the main means of controlling units in the [Ukraine war] zone."
"It will be very sad and at the same time funny if the catalyst for changes in approaches to communications and control in the [Russian] armed forces is the arrest of Pavel Durov," the channel said. "And not the purely military problems that had accumulated over two years, to which the relevant department for some reason preferred to turn a blind eye."
Russian newspapers published Monday also focused on Telegram's future, running articles asking: "If Telegram crashes, how will [our army] fight?" and suggesting that Telegram "might become a tool of NATO."
State-run news agency Tass reported that Kremlin press secretary Dmitry Peskov declined to comment on the matter during a press briefing on Monday.
"We don't know yet what exactly Durov is accused of. We haven't heard any official statements on this matter yet," Peskov said. "Without this, it would be wrong to make statements."
President Emmanuel Macron said that the French government was not involved in the arrest of Telegram founder and CEO Pavel Durov.
He said that while Telegram's president's arrest on French territory occurred as part of an ongoing judicial investigation, it was not a political decision and up to Judges.
Durov, who founded the messaging app in 2013, was detained Saturday night after his private jet arrived in Paris. The Paris prosecutor has not yet communicated the reasons for his arrest.
The tech chief currently remains in police custody. The arrest follows probes "accusing Telegram of being complicit in numerous affairs linked to drug trafficking, apology for terrorism and cyberbullying," French daily Le Monde reported.
In a statement, Telegram said that its CEO -- a Russian-born French-Emirati citizen -- had "nothing to hide" and that the company abided by EU law.