Final answer:
O'Neill tried to improve relations with the republic in order to encourage compromise and address uncertainty among northerners. The aim was to avoid involvement in European conflicts and foster friendly trade relations.
Step-by-step explanation:
The attempt to improve relations with the Republic can be attributed to the desire to encourage compromise between the two sides before leaving office. By doing so, O'Neill aimed to address the uncertainty among northerners regarding the appropriate response to the southerners' move. The goal was to foster friendly trade relations and avoid political alliances that could involve the nation in European conflicts.