Kanye West's most recent apology for his antisemitism is falling flat ... at least as far as Rabbi Shmuley Boteach is concerned.

Rabbi Shmuley, an influential American rabbi and TV personality, took a blowtorch to the full-page ad Ye took out in The Wall Street Journal apologizing to "Those I've Hurt."

Ye, in part, blamed a car crash that nearly killed him 25 years ago for his hate speech ... but the rabbi says Kanye is far from the first person to blame a blow to the head on antisemitism. Then he doubled down and insisted his apology is not a P.R. stunt ahead of his album release Friday ... Boteach is calling B.S.

Rabbi Shmuley says Ye is a straight-up "American Nazi" and the biggest thing missing from the apology -- which Shmuley says probably cost around $75,000 -- is any mention of Kanye's "Heil Hitler" track.

Shmuley lives in Miami and says the song is being played in clubs in Miami and beyond ... and he tells us the three things he thinks Ye needs to do to make his apology feel more sincere ... watch the video.

Bottom line ... Rabbi Shmuley says Kanye has Jewish blood on his hands, albeit indirectly, and he unloads on him in epic fashion here.

Oy vey!