http://biz.yahoo.com/rb/081006/business_us_americanexpress.html?.v=1
It seems that Amex failed its own internal financial review. It might not be able to make its own minimum payments and might have to ask for CLIs from the taxpayer.
Needing to remedy its own credit problems, Amex has been decreasing taxpayers credit limits.
Amex is taking those and other adverse actions in the hopes that it won't have to ask the taxpayer for a credit limit increase in order to avoid going bankrupt itself.