New Delhi, Sept. 20 -- History rarely offers neat repetitions, but the Saudi-Pakistan defence pact announced this week bears an uncanny resemblance to another turning point: Britain and France's humiliation during the Suez Crisis of 1956, when the postwar illusion of European dominance collapsed overnight.

Then, as now, the moment was defined not by a battle lost, but by a trust betrayed. What Suez revealed for London and Paris, Riyadh has just revealed for Washington: that the security guarantees of an old patron are sometimes just not good enough.

The pact follows on the heels of Israel's strike on Qatar, which laid bare the fragility of American security assurances in the Gulf.

For decades Saudi Arabia was the archetype of an Americ...