CSIS's definition reads like a BA thesis
"First, right-wing terrorism refers to the use or threat of violence by sub-national or non-state entities whose goals may include racial or ethnic sprmcy; opposition to government authority; anger at women, including from the in[cel]... movement; and outrage against certain policies, such as abortion.6 This analysis uses the term “right-wing terrorism” rather than “racially- and ethnically-motivated violent extremism,” or REMVE, which is used by some in the U.S. government.7 Second, left-wing terrorism involves the use or threat of violence by sub-national or non-state entities that oppose capitalism, imperialism, and colonialism; pursue environmental or animal rights issues; espouse pro-communist or pro-socialist beliefs; or support a decentralized social and political system such as anarchism....Fourth, ethnonationalist terrorism refers to violence in support of ethnic or nationalist goals—often struggles of self-determination and separatism along ethnic or nationalist lines."
Opposition to government authority can come from any political orientation. BLM ritos qualifies as do the 100s and 100s of bombings in 70s by left radicalss.
"anger at women, including from the in[]cel movement". leaves me speechless.
"outrage against certain policies, such as abo][rtion." What? So left terrorism cannot be born out of such outrage against policies?
all of the components of left terrorism can be subsumed under the components listed for right terrorism. enormous difference in abstraction between right and left. right includes outrage against certain policies and anger at women, no similar components are defined for left. Components of left are such narrow things as capitalism, colonialism, and imperialism.
question about what's the difference between right and ethnonationalist is more apt than could ever be imagined. The former includes racial or ethnic sup][remacy and latter ethnic or nationalist goals. They are conceptually indistinguishable, the former is subset of the latter.