Analysis of Antagonists

WHAT though the neutral sea sever us twain?
 In the still night your soul in mine I take;
 Your eyes, hilarious with passion, wake,
 And love's delirium is mine again,
 When all your body's warmth swirled in my brain—
 Your face uplifted like a pallid lake
 Where in my eager lips their thirst could slake,
 With deep-sighed, langourous kisses, keener than pain.  
  Then suddenly through passion's rosy mists
 A shudder trickled, like a stream of blood:
 In a grim pause we felt and understood.
 The everlasting war that was our fate—
 The pitiless struggle and primeval hate
 Of old implacable antagonists.