Inner
口 — the walled territory being guarded by the halberd. Combined with
戈 the picture is unmistakable: a fortified zone with armed defender. This is the original
或 = 'a country, a region.' The land-meaning later got the
囗 enclosure added around it to become
國/
国, freeing
或 to drift into 'either/or, perhaps' through phonetic borrowing.