It has been a little more than two weeks since President Biden greeted Crown Prince Mohammed bin Salman of Saudi Arabia with a fist bump while visiting Jiddah. A key purpose of Mr. Biden’s trip, which constituted a face-losing reversal of his previous efforts to isolate the brutal Saudi regime, was to get more oil production from the kingdom — and gas price relief for US motorists. MBS, as the Saudi leader is known, has just responded with his own gesture: an upraised middle finger. The flip-off wasn’t literal, to be sure; figuratively, though, the description fits Wednesday’s announcement that the global oil cartel Saudi Arabia leads will boost monthly production by a mere 100,000 barrels, or 0.1 percent of global demand for crude.