Can 'on the ground' mean "inside the building"?
However we have strong grounds to believe Ukrainian forces deliberately targeted the hospital for attack as they believed—falsely—that there were insurgents on the ground.
English Language Learners Stack Exchange is a question and answer site for speakers of other languages learning English. It only takes a minute to sign up.Sign up to join this community
It's commonly used to mean "present." An older phrase meaning roughly the same thing is "on the scene." I have seen more than one essay on writing style that noted that "on the ground" can usually be deleted with no change in meaning but an improvement in the result. Here, instead of deleting it altogether, you might replace it with one of the options already mentioned or simply with "there."
I think that use is an error. It should have said "on the grounds", with an "s". That would mean the same as "on the premises". In this example, that would mean there were insurgents within the hospital or on the land where the hospital is situated.
The phrase "on the ground" is used also, but in talking about insurgents, it would mean that they came in by air, and were now actually on the surface of the earth in the area.
After comments, I am retracting the claim that "on the ground" means they arrived by air. What I continue to assert is that "on the ground" doesn't mean "located within a small area", but their general existence in a wide area, which would not be a justification for an attack on a localized installation like a hospital. I believe the simplest explanation is a typo for "on the grounds".