Exactly, you don't roll fighter aircraft around the target aircraft on a professional, safe intercept, look what happened in the past, its is very dangerous, for both aircrews, but particularly for those on the surveillance aircraft, so yes this was a very "low brow" approach to conducting a legitimate intercept. Maybe "thuggish" is the word that best describes this type of behavior, the US aircraft always maintain course and altitude when being intercepted.
I can assure you that US aircrew do not "krap" their pants as Mangi has suggested on more than one occasion, but that's rather unprofessional as well, to denigrate others and call them names.
I can assure you, that we will conduct to conduct air ops of all types in international airspace, international law, and most nuclear treaties allow that type of surveillance in order to verify that those whom are parties to those treaties keep the terms of those treaties....
Anyway, both China and US have an agreement to conduct flight operations with-in a very specific set of guidelines, target aircraft are to maintain course and heading when being "joined" by the intercepting aircraft. Military traffic follow those protocols to the letter, when someone breaches those guideline, a formal complaint is logged with the offending party, and both sides will negotiate in order to bring everyone back into compliance. We'll see how this plays out, while some think that "bullying" is acceptable, we of course do not practice bullying, nor do we appreciate bullying, whether its ourselves or others who are the recipients.
It's called "innocent passage" vesicles, and that is also spelled out under treaty, you are unarmed and observing, gathering intelligence and conducting your survey, so no, that is the very definition of professionalism, the Russians conducting intelligence gather have been following those very specific protocols, and as long as they do, there's "no harm, no foul".
for posters on the SDF who don't understand the terms and conditions of these protocols, I would suggest you do a little research before casting judgement on others... end off topic, this is the "Chinese purchase of the SU-35 thread, and while I agree that possibly the SU-35s, (there are 4 aircraft in China at this time), will eventually conduct some of these details, its most unlikely that those 4 Flankers are a real factor in any intercepts for some time.