I've already stated this pretty clearly and repeatedly, so I'm not sure this point is getting through, but the reason you absolutely may NOT use the MD degree is because:
In the U.S., we have two ways to become a licensed physician: MD & DO. If you get into a school that grants one of these two degrees and complete the curriculum, you are granted the degree upon graduation and THROUGH THAT DEGREE, you are eligible to take the USMLE and become a fully licensed physician. Your degree and your medical license are two different things. Your degree denotes your schooling, your license confers practice rights. As a DO, you have the opportunity (just as an MD does) to become a fully licensed physician in the US. It is 100% unnecessary for you to claim the degree "MD" behind your name, because you DID NOT EARN IT. You earned a DO. If it makes you feel any better, I don't like that foreign doctors use "MD" either, based on the same reasoning. Maybe you'd prefer that they use "DO"? I'd be okay with that. But if they use their foreign degree, you don't see the MBBS's whining about not being able to call themselves MBChB's. Why? Because they didn't earn it, and they're the same thing. But the reason their degree is converted into an American MD is because their degree is equivalent to an allopathic medical degree (MD), not an osteopathic medical degree (DO). Find me a foreign degree that's the equivalent of a DO and I'll help you lobby to require that foreign doctors use "DO" when they come here to practice. Foreign physicians are trained in the "allopathic model", which the DO community has worked hard to establish as distinct from their training. If you want to acknowledge the full equivalency of the DO degree to the MD degree training, then I'm all for it. Eliminate the DO degree altogether and we'll all be happy. But you can't just pick and choose..."hm, I'm feeling like a DO today" when and where to use your real degree.
And opening up the use of "MD" to DO's is not only insulting (I would never ask to be able to use "DO" alongside my name, I think it's disrespectful to students who went to DO school and earned DO degrees), but it would set a dangerous precedent. Once you say, "ok, anyone with a medical license who passes the USMLE can use 'MD'", who else do you think is going to elbow their way in there? Go over to the Podiatry forums and look at how much they talk about how their training & education are basically the same as a medical student's and how they're all "doctors" and "medical students" and "physicians". Read up on some of the DNP propaganda. They claim they're the same as a doctor. They're trying to get the NBME to write them medical licensing-like exams. Who else is going to elbow their way in? At DMU, I believe there's a pretty closely integrated DO & DPM program. How would you feel if all of a sudden they started demanding that they be able to use your degree after their name because THEY FEEL theirs and yours were close enough? After they had specifically chosen podiatry school, knowing full well they'd be required by law to use the DPM degree?
To summarize, the point is:
1) You still haven't answered WHY you want to use the MD degree (but not convert it), when yours allows you to do everything an MD does anyway
2) The only reason (based on 1) therefore to do so would be cosmetic. It's no different than the sketchy caribbean "convert your DO to an MD degree!" scams you see advertised
3) You can't say "we're separate and distinct and special and proud to be DO's" and at the same time say, "...but we should be able to use MD when it suits us"
I agree with you that the foreign doctor being allowed to use MD while a domestically trained DO cannot is in a way inconsistent. I think it's irresponsible and inappropriately ambitious for people to use that inconsistency as a means to satisfy ulterior motives that will have such widespread repercussions, especially when it's so blatantly unnecessary.