New Delhi, Sept. 9 -- Tit-for-tat strikes by the US and Iran sent Brent crude oil prices within sniffing distance of the psychologically key $100-a-barrel mark on Tuesday. The Houthis-an Iran-backed Yemeni rebel group-attacked four Saudi Arabian cities, setting fire to some oil facilities after the US struck three of Iran's oil tankers.

The White House has been claiming to have wiped out Iran's navy and air force, but Tehran's record of retaliation shows the firepower it retains. Some of it is through regional proxy militia, its grip over which doesn't seem to have loosened as much as recent reports of their going their own way would suggest.

The latest flickers of hostility are an omen that this conflict may escalate as US midterm elec...