Even when they appear to be sans serif fonts, the roman glyphs of many of these non-Western typefaces turn out to be common serif faces with those serifs chopped off.

I believe we are looking at a version of Times New Roman Bold or Extra Bold—minus its serifs.

A sans serif that comes close is Intrinseca:
http://www.myfonts.com/fonts/aviation/intrinseca/

Thanks. It's possible, but I'm struggling to imagine a serif-less Times New Roman Bold looking close enough to these characters, because all the thin strokes would need to be thickened as well. Still, perhaps that's what was done...

Don't know either the origin font of this specific Latin counterpart. Those who mimic this style are mainly illegal chopped-off serifs Times or bad attempts to create a "Times Sans Serif" ('Times Sans Serif', 'Balham', 'TimesNoRoman'...). The only fair sans-serif rework I know is Jason Vandenberg's Bodoni Sans but it's obviously not based of Times New Roman.

The topic has come up here before:
http://typophile.com/node/119034

I'd like to know what the original font for all these typefaces is.

Presumably one developed internally by the "MN" foundry to fill the latin codepoints of their non-latin typefaces.

It's generally known as "MN Latin" designed by Muthu Nedumaran for Murasu Systems's indec fonts bundle that comes with the MacOS.