If the War of the Ring can be considered a just war, there are nevertheless important caveats. First, the allies of the West use the Rangers of Ithilien as masked and camouflaged resistance fighters to ambush troops on the move, which could equally be considered terrorism - as suggested by Kirill Yeskov's novel The Last Ringbearer (1999), a rewrite of The Return of the King from the point of view of the Orcs.
I read this line and turned to my wife with all the fury of a man who received a B+ in "The Fundamentals of International Law" in undergrad.
"Terrorism"? The Geneva Conventions, to which Gondor is a signatory party, clearly state a lawful combatant is i) commanded by a person responsible for his subordinates, ii) has a fixed distinctive sign recognizable at a distance, iii) carries arms openly, and iv) conducts operations in accordance with the laws and customs of war. Mordor is going to claim terrorism because Captain Faramir, leader of a military unit with a clear chain of command, each of whom bears the sigil of the tree of Gondor, hid in some bushes before they attacked an occupying force?
Any credible judge would laugh that claim straight out of court. Absurd.