For an hour on Monday, President Vladimir V. Putin and his defense minister presided over a televised, annual meeting of the Russian military’s top brass. They held forth on NATO, Ukraine and issues as obscure as mortgages for service members.

But one topic went unmentioned: Syria.

Mr. Putin has yet to say anything in public about the collapse of his close ally, Bashar al-Assad, in Syria more than a week ago, even as Russia struggles to salvage what influence it can in the Middle East. The silence underscores the uncertainty surrounding the future of Russia’s military bases in Syria — and the overwhelming priority for the Kremlin that the war in Ukraine has become.

Mr. al-Assad’s fall is a painful topic right now in Moscow, said Anton Mardasov, a Moscow-based military analyst focusing on the Middle East. “It’s better not to say anything.”

Things were very different just a year ago, when Sergei K. Shoigu, then the defense minister, boasted at the same annual meeting that Russian troops remained deployed both in Syria and Nagorno-Karabakh, the Armenian-populated enclave that Azerbaijan recaptured from Armenia last year.

“Russian groups of forces remain the backbone and the main guarantee of peace in Syria and Karabakh,” Mr. Shoigu said at the time.

Russian peacekeeping forces pulled out of Nagorno-Karabakh in May, a sign of Russia’s loss of influence in the Caucasus region, which had been part of the Soviet Union.