【闭关锁国】〖bì gun su guó〗[cut off one's country from the outside world; avoid having contacts with other countries; close the border; close the communication at the borders]

闭门却扫谍渗入，

关口紧封外企拒。

锁断往来朝强硬，

国仇家恨造核武。

闭关自守，不与外国往来。Are closed outside world, not deal with foreign country come go.同：闭关自守、故步自封。反：门户开放、面向世界。