The poem is talking about the memories of the old days or the past where everything seems to be tranquil at its peak.
People smile even after being hit or after facing comflict footings without any slam of war.
The poem talks about union and smile at the reach of peace in stanza 2.
Although we might by some chances face war but it has not stopped us from progressing in harmony.
At the end the poet persona makes use of a suggestion and a wish–He wishes to find the old days where harmony lives in Tranquility.
Read and enjoy more of having tranquility 💙