I never claimed that the Border Worlders were saints. I said that what they were doing was nowhere near the level of what the Black Lance were doing. The Border Worlders fought for their interests, of course, (there are very few countries that don't) and in the process they helped save Confed's bacon. They fought for survival and to prove their innocence. They did what any other country would. The Black Lance, on the other hand, went out and killed people to provoke a war, both Confeds and Border Worlders, and in the process comitted war crimes.
What I have an issue with is the idea that the Border Worlders were meant to sit back and take it passively, and if they didn't, they somehow became the aggressors, and Blair becomes a traitor for helping them. Their ships had come under attack, their territory had been invaded by Confed forces, their worlds were coming under increasing attack from Confed or Confed backed forces (including that Circe attack you mentioned), so when they saw a chance to dent the military capbility that was being used to hurt them and hopefully gain some respite, they took it. That's a very valid military tactic. How might the battle at the end have turned out if the Princeton had been fighting againt the Border Worlders instead of for them?
Were the Border Worlders saints in WC4? No. Were the Confeds saints in WC4? No. Does any of that in any way justify or mitigate what the Black Lance did? No. Does any of what the Border Worlders did make Blair a traitor to Confed? No. By doing what they did, the Border Worlders brought the Black Lance in to the open, and Blair played a huge part in that. Whatever we might or might not agree with regarding their tactics, the fact is that they were successfull using those tactics. (They might have been successfull with other tactucs, but then again, they might not.) They might not have been saints, but they did prevent a huge massacre of Confed citizens. That was why the Confed Senate gave Blair a promotion at the end of WC4 instead of a jail sentence.