建交
jiàn jiāo · HSK 7
to establish diplomatic relations
🤝 建 (establish/build) + 交 (relations/exchange) = build relations
建 means to build or establish (as in 建立); 交 means exchange or relations (as in 交流, 外交 = diplomacy). Together: two countries build formal ties, i.e. establish diplomatic relations.
建 — 廴 (stride radical) + 聿 (writing brush)
Originally depicted a hand holding a brush (聿) combined with the 廴 'stride/extend' radical, suggesting drawing out or laying down lines. From this came the meaning of setting up or establishing, as in marking out the foundations of a building. Today it broadly means to build, establish, or construct.
交 — top 亠 + 父-like crossed legs
Originally a pictograph of a person standing with legs crossed, showing the idea of crossing or intersecting. From this concrete image, the meaning extended to abstract senses like 'exchange,' 'interact,' and 'hand over.' Modern uses such as 交流 (exchange) and 交通 (traffic) all trace back to this core notion of crossing.