Why is the relationship between the highest levels of US Gov (Treasury Department) and Saudi Arabia hidden from us?

A recent Bloomberg News story suggest: “Saudi Arabia’s Secret Holdings of U.S. Debt Are Suddenly a Big Deal”  Bloomberg tells us: “Saudi burns through $100 billion of reserves as strains emerge”… “It’s a secret of the vast U.S. Treasury market, a holdover from an age of oil shortages and mighty petrodollars: Just how much of America’s debt does Saudi Arabia own? But now that question — unanswered since the 1970s, under an unusual blackout by the U.S. Treasury Department — has come to the fore as Saudi Arabia is pressured by plunging oil prices and costly wars in the Middle East.” … “In the past year alone, Saudi Arabia burned through about $100 billion of foreign-exchange reserves to plug its biggest budget shortfall in a quarter-century. For the first time, The signs of strain are prompting concern over Saudi Arabia’s outsize position in the world’s largest and most important bond market.”

Editor CEC Asks:  Why does out country owe money to these hand and head choppers, who many think are behind ISIS?  And why is our debts to them not openly published like other debts?  It is no secret that the Saudis are a big ally in weakening the governments of Syria, Iraq, and Iran, to name a few.  Maybe Bloomberg should ask Donald Trump and Hillary, if either of them would ditch this disgusting crony if elected?