If the definition of “terrorism” is violence targeting civilians to spread fear in furtherance of a political motive, then the assassination of Iranian scientists certainly qualifies as terrorism. It should be condemned as such. It’s also an unwise strategy.
The editorial gets it wrong from the outset. The scientists were not killed to "spread fear in furtherance of a political motive." They was specifically targeted to slow down the development of nukes that will be used to wipe out Jews and other kafirs, i.e. as a tactic in an ongoing, existential war. Surely even an exquisitely sensitive and peace-loving editorialist can see the huge difference between "terrorism" (which such types never shy away from using when referring to non-Muslims, but tend to shun when jihadists employ it) and that.