To Lucasta, Going to the Wars
Dude's hawkish if you ask Shmoop. We mean really. He's willing to ditch his honey (who sounds really awesome, by the way) for battle, where he might get shot and die? Now that's patriotic zeal.
This guy's all about honor, even if it means hurting his ladylove's feelings. In fact, his feelings for her seem somehow tied up in his sense of honor. Earning honor is the way he earns the right to love Lucasta. And while that might not make a lot of sense to us modern folks (chivalry's dead, isn't it?), back then that kind of talk was all the rage.
He's kind of like the Atticus Finch of the 17th century. Sure, he knows that he might be headed into a losing battle. But if he doesn't go fight the good fight, he won't be able to face his loved ones with any kind of pride. So while we may question his zest for battle, in the end it makes a fair amount of sense.