The Obama administration on Monday confronted the fundamental contradiction in its increasingly tense relationship with Saudi Arabia. It could not bring itself, at least in public, to condemn the execution of a dissident cleric who challenged the royal family, for fear of undermining the fragile Saudi leadership that it desperately needs in fighting the Islamic State and ending the conflict in Syria.

The United States has usually looked the other way or issued carefully calibrated warnings in human rights reports as the Saudi royal family cracked down on dissent and free speech and allowed its elite to fund Islamic extremists. In return, Saudi Arabia became America’s most dependable filling station, a regular supplier of intelligence, and a valuable counterweight to Iran.

For years it was oil that provided the glue for a relationship between two nations that share few common values.

Today, with American oil production surging and the Saudi leadership fractured, the mutual dependency that goes back to the early 1930s, with the first American investment in the kingdom’s oil fields, no longer binds the nations as it once did.