The most significant and telling line in Wilfred Owen's poem "Dulce et Decorum Est" is the final line saying, "Dulce et Decorum est Pro patria mori," which is Latin, meaning, "It is sweet and glorious to die for your country" (14-15). The poem was written at the same time period as World War I and describes the combat and bloodshed that took place during that war. The connection between the poem "Dolce et Decorum" and Romeo and Juliet is that both deal with the themes of violence and even war in a sense. In addition, both the poem and the play take a moral stance on the issue of violence or war.
One of the central points in the plot to Romeo and Juliet concerns the fact that both Romeo and Juliet were born to families engaged in a longstanding feud, even an "ancient" feud, as the First Prologue describes it (3). The feud between the two families has created a great deal of bloodshed. It has even created whole-city brawls because all of the citizens of Verona have taken sides in the feud, as Prince Escalus explains in his lines:
Three civil brawls, bred of an airy word
By thee, olda Capulet, and Montague,
Have thrice disturb'd the quiet of our streets
And made Verona's ancient citizens
Cast by their grave beseeming ornaments
To wield old partisans, in hands as old,
Canker'd with peace, to part your canker'd hate. (I.i.85-91)
In other words, Prince Escalus is saying that while the elderly citizens of Verona had lain down their weapons in peace, they have now picked them up again and taken sides on the issue between the Montagues and Capulets once again in an effort to re-establish peace.
However, the two pieces have more in common than just a running theme about violence. Both pieces take a stance on the morality of violence. The poem's stance is seen in the final few lines of the poem:
... you would not tell with such high zest
To children ardent for some desperate glory,
The old Lie; Dulce et Decorum est
Pro patria mori. (13-15)
These lines are significant because they mark a change in perspective concerning war. Throughout the ages, up until World War I, the common belief was that war was glorious. It was not until World War I that humanity finally saw the brutality and senselessness of war, and this brutality is clearly depicted throughout Owen's poem. Prince Escalus also points out the senselessness of war, even on a small scale like a family feud, by pointing out how many deaths their feud has caused, such as Romeo's and Juliet's deaths. Escalus even points out that he, too, has lost a "brace of kinsmen," meaning many family members, such as Mercutio.
Hence the connection between "Dulce et Decorum Est" and Romeo and Juliet is that both expose the horribleness and senselessness of violence through fighting.