One would hope, but ...

[Saki6]

Area Ukrainian Americans distraught over Russian raid

Distraught. That’s how Paula Duda Holoviak summed up her reaction to the Russian invasion of Ukraine, the land of her heritage. “I’m so upset. I’m having trouble focusing on my day job,” said Holoviak, a…

www.republicanherald.com

“We hope they don’t attack the historic churches. One would hope, but there’s no guarantee. These are UNESCO world history sites.”

Is "one would hope" a set phrase? What does it mean?

 

[Tarheel]

Yes, it's a set phrase. It simply means that's what they hope will happen.