In the opening of Agamemnon, the Chorus of Argive Elders speaks out about their concern regarding Agamemnon and Menelaus leaving for Troy in order to rescue Helen (the wife of Menelaus). It took the men 10 years to force the fall of Troy. The elders were angry because the men left with a huge army (and the elders were not sure if the battle was worth it). The elders were left to take care of themselves. They know that they are growing weak and cannot do the things they were able to 10 years earlier.
As the elders continue to contemplate Agamemnon's battle with Troy, they voice their concern about the many lives the war took. Once the Herald verifies that Agamemnon is on his way home, he gives the elders some bad news: Menelaus and his ship disappeared in a storm. The Herald does not know if Menelaus will return.
Agamemnon returns and the elders say that they were sorry for questioning his actions. They, now, understand the importance of the war with the Trojans and support his decision to leave completely.