Yes military targets, as are most energy production facilities. Any part of critical infrastructure is a prime military target. Just ask the people of Taiwan.

This has nothing to do with terrorism and certainly isn't a reason not to build them. Whatever replacement you have for them, would then become the target. This is common sense.

I would also say that being energy independent is a deterrent to all out war, as it removes leverage one party may have over another. With a balanced field of power, total war becomes less likely.

Also by the time Western Europe / Mainland US is under military assault and our allies can't protect our critical infrastructure, we have much bigger concerns.