對這件事情有點興趣爬文然後搜尋了一下。
https://www.theguardian.com/world/2022/feb/11/biden-7bn-frozen-afghan-
reserves-taliban
The money – which includes currency, bonds and gold – mostly comes from
foreign exchange funds that accumulated over the past two decades when
western aid flowed into Afghanistan. But it also includes the savings of
ordinary Afghans,
被凍結的資產，主要來自於外匯基金，在這二十年西方援助環境中，積累起來。
但也包括了普通人的存款。
https://www.dailysabah.com/business/finance/low-on-dollars-afghan-currency-
reserves-mostly-inaccessible-to-taliban
Central banks, especially in developing nations, often park their assets
overseas with institutions such as the Federal Reserve Bank of New York
(FRBNY) or the Bank of England (BoE).
“As per international standards, most assets are held in safe, liquid assets
such as Treasuries and gold,” Ahmady said on Twitter, confirming assets were
all held at the Fed, BIS, through the World Bank program or other bank
accounts.
開發中國家，以及此例中的阿富汗，把大部分資產放在海外，以流動性資產的方式存放。
https://tolonews.com/business/central-bank-reports-increase-foreign-
exchange-reserves
In 2018, Afghanistan’s revenues from currency exchange reached $100 million
which has been unprecedented in the recent years, the Central Bank governor
Khalil Sediq said.
He also proposed that the money should be invested in the creation of an
agricultural loan bank or in something else that can bring more money to the
country’s treasury.
2018靠外匯換匯賺很大，並且更強調投資循環生財。
In Afghanistan, however, still, around 50 percent of the development budget
comes from foreign support.
儘管有50%的發展預算仍來自國外援助。
========
不算專業的拼湊理解是:
這無關於貿易順差，而是一個技能樹有點歪，
在順境下投資頗成功，但又把主體資產放在海外的銀行。
(那些錢的來源跟西方援助有間接關係，但卻又不是直接把帳混在一起)
所以其實凍結本身銀行沒有說什麼，可能還慶幸錢沒落在塔利班手裡，
但說要分錢給美國911受害者他們就抗議了，強調錢是人民的而且來路正當。