If you've read what we have to say about the themes of "Love" and Warfare," then you already know that one's political duty can often interfere with one's personal relationships in this play. Troilus and Cressida's romance is thwarted when Cressida is traded to the Greeks, Achilles is highly criticized when he chooses his love life over his military duties, and so on. The irony of all this is that the Trojan War is being fought because of Paris' personal (read: sexual) relationship with Helen. Ultimately, the play raises the following questions: Why does Paris get to go to war over Helen when all the other personal and romantic relationships in the play have to suffer? And why the heck should there be so much death and suffering just so one couple can be together? In a larger sense, the play is asking us to think about a larger, more universal issue: when it comes to political and military duty, soldiers and their families are required to make personal sacrifices in order to further the interests of their countries. Troilus and Cressida argues that in some cases, this is completely unfair.
Paris is the only Trojan whose life benefits from the Trojan War—everybody else's suffers.
Even though most of the Trojans think it's wrong to fight the war in order to keep Helen, their sense of public duty leads them to support the war anyway.