What cultural beliefs is Owen questioning in the last two lines? Could this conclusion still be controversial today?
In the last two lines of the poem, Owen is questioning the idea that it is "dulce et decorum est pro patria mori" or sweet and right it is to die for your country.
I do not believe that this would still be controversial today, or at least not very controversial. Today, we no longer talk about it being a great thing to die for your country. We do honor those who do so, but we don't glorify it as an ideal way to die.
So today, we see death in war as more of a necessary evil, but not as a positive good. Therefore, these last two lines wouldn't be all that controversial.