Nice history lesson GSchnitzer.
For Star Trek (please correct me if I'm wrong), it always seemed that the second NCC-1701D entered the neutral zone, the Romulans were sending ships. It's been a few year since I watched it, but it also seemed that Romulans often had business with planets inside the neutral zone or were encroaching more often and with less consequence than the Federation. And you know they probably had a whole bunch of cloaked ships in there
Little summary I found with some help from Google: