你要真感兴趣的话不妨查查财政部对于这新加坡所谓外债的官方解释?
https://www.mof.gov.sg/news-publications/media-articles/askST-Why-does-Singapore-have-an-external-debt-of-US1-766-trillion-
"As a major financial centre, Singapore receives large inflow of capital from overseas and a substantial portion of this money is deposited with its banks. This is recorded as external liabilities or borrowings."
外国流入新加坡的大量资本存在银行,这就是所谓的"外债"!