Confused by an XDF SC.

nina23

Developing nations in various parts of the world have  amassed $700 billion in debts; at stake, should a significant number of these debts be repudiated,is the solvency of some of the world's largest multinational banks.

above is the question with the correct answer.I am confused about the structure and meaning of the underline part.thank you for helping!

dullpen

正常语序：
if a significant number of these debts should  be repudiated, the solvency of some of the world's largest multinational banks is at stake
前半部分虚拟语气一个倒装，整个句子又是一倒装。双重倒装。此句很经典。

be  at stake的解释：
if something that you value very much is at stake, you will lose it if a plan or action is not successful  
They have to win the contract - thousands of jobs are at stake. National pride is at stake in next week's game against England.