Not even close, while most current terrorists are Muslim, the Provisional IRA, Bader Meinhof Gang, the Italian Red Brigades, and FARC in Colombia are or were examples of non Muslim terrorist groups.
Historically the KKK, Viet Cong, and various anarchist groups would qualify.
Islamic terrorism is just the most prevalent current flavor of man’s inhumanity to man.
How many of those groups had a stated goal of worldwide subjugation of anyone not actively participating in their terrorism?
With a 1400 year track record of inhuman barbarity, I would say they are the most persistent..
None of them were known to behead living human beings, or work for world domination, or stone women to death, or burn captured humans in cages, or run down children & women & men using trucks.
But the muslims are doing it for allah.