NEW YORK, Sept. 23 -- When President Trump told reporters on Wednesday that the United States was "hopefully towards the end" of its seven-month war with Iran, the oil market believed him before Tehran did.

Brent crude fell for a fourth consecutive session on Friday, settling near $101.80 a barrel as traders priced in a diplomatic outcome that the record does not yet confirm. West Texas Intermediate dropped toward $100. The combined four-day retreat from Monday's $108 intraday peak erases more than six dollars of the war premium that accumulated after Iranian drone strikes sabotaged Saudi Arabia's East-West pipeline eight days ago.

The catalyst for the sell-off is a summit scheduled for September 22, a meeting between Trump and leaders ...