How do I solve 2 down in Times Cryptic 29550?

Question

Accepted Answer

2 down reads "Opponents of US with American motif" (5 letters); the answer is THEMA. It's a charade: the answer breaks into parts in clue order, each part clued by a word or short phrase. No indicators needed; watch for standard abbreviations (RA = artist, US = American, IN = at home) and short synonyms. The full step-by-step breakdown is on this page.

Opponents of US with American motif (5)

2D — Opponents of US with American motif (5) — THEMA