Countries and realms with 国

The older writing 或 already represented a country or territory before 國 became established. The Chinese University of Hong Kong identifies 國 with an outer enclosure in Western Zhou bronze inscriptions. It analyzes 囗 as a boundary sign and 或 as the phonetic component. Its examples include the Cai Hou bells, where 國 denotes a state. An earlier 或 in the He zun inscription can be interpreted as 國 or 域, so that example does not settle a sharp distinction between country and region. CUHK Multi-function Chinese Character Database

The Japanese dictionaries differ in emphasis. Kanjipedia classifies 國 as combining meaning and sound. Heibonsha’s Jitsu instead classifies it as semantic composition, interpreting 或 as a settlement defended with a weapon and the added enclosure as an outer wall. Jitsu gives the capital settlement as the original referent, whereas CUHK gives the state. A historical phonetic role does not supply an ordinary modern Japanese reading for 或. Kanjipedia, Jitsu

For the modern shape, Kanjipedia explains 国 through the variant 囯 with an added dot. Taishukan’s Kanji Bunka Shiryokan also considers development from cursive 國. It documents the dotted 国 beside 國 in a 1589 edition of Unpo Irohashu, so the shape predates postwar standardization. Its first appearance and the exact route to that shape remain uncertain. Reading the modern 玉 as a treasure inside a country’s walls would be a memory aid, not the documented ancient formation. Kanjipedia, Taishukan