WTI crude oil is -0.65% to $106.95 a barrel, although up from earlier lows, as the prospect of a U.S. military attack on Syria becomes less certain. However, Brent is +0.15% to $114.18.
Investors should sell Brent if an attack causes futures to rise, Morgan Stanley said.
"Eroding oil fundamentals already point to a weakening of Brent prices," analyst Adam Longson wrote. "Without significant contagion, we are unlikely to see any real supply disruption related to Syria.