This remains the key problem for Trump ... we & others have reported that top US military officials do not believe air power alone can achieve the outstanding objectives.
And US military officials do not believe the type of bombing we've seen recently is likely to move the needle as far as talks w/ Iran go.
But at the same time, Trump has appeared reluctant to "go all in" -- as one source recently put it to me -- from a military perspective, which would almost certainly require US ground troops.