(covers information from several alternate timelines)
Background information Edit
Although not mentioned by name in either episode, the appearance of the Renault FT in the opening credits, indicated that the vehicle was manufactured and used in the mirror universe as well.
Both clippings originated from the 1927 Paramount Pictures silent – as in no dialog – World War I aviation film Wings (the very first "Best Picture" Academy Award winner), and are in effect one and the same, albeit flipped – or "mirrored" if you will. Shot on location near San Antonio, Texas, the Star Trek-used clipping with the Renault FT tanks was part of a larger sequence depicting the 1918 Battle of Saint-Mihiel, which was originally included on a 1985/1989 reissue version of the film released on VHS by Paramount Home Video, from which the Enterprise producers lifted the clippings for use in the series, cleaned-up and hue corrected in post-editing to match the rest of their respective chronology sequences. It was trimmed though from the already extensive Battle of Saint-Mihiel sequence on the 2012 remastered release.  This restored and remastered version was released on the occasion of the studio's 100th anniversary and the film's 85th, and on which Ben Burtt had worked as restoring sound (effects) editor. 
The tanks shown, actually concerned the American made M1917 light tank standing in for its French original, the Renault FT tank.  Being licensed built copies, production only started in 1918, and none reached the frontlines during World War I, the American forces instead using the French originals.