Were Tolkien's orcs a metaphor for minorities?

He seems to have associated events and characteristics with the Orcs that we today would rather refer to when speaking of a very specific Race.

Turakas. Or as the World in general knows them- Turks.

The Romanesque-underpinings of Numenor- and in succession, Gondor, the textbook-copy of the Siege of Vienna that is the battle of Pelennor fields- right down to the Polish charge upon the Orkish siege lines, the repeated association of the East and South with evil arrayed against the Eru-worshipping West. And of course, Tolkien himself described Orcs as "...squat, broad, flat-nosed, sallow-skinned, with wide mouths and slant eyes; in fact degraded and repulsive versions of the (to Europeans) least lovely Mongol-types."

That was when he wasn't talking about their “dark skins”.

The Legendarium is the story of the British Empire, heir to Rome, warring against the “evil” Turkish, Indian, and Chinese as the 20th Century dawned. A well-written story, of course, but anyway…