The Bhagavad-Gita advises to renounce longings for worldly possessions such as riches, fame, family, property and the likes. That is why the poet says that every country is home to one man and exile to other. If a man is conscientiously performing his duty in another country, irrespective of the country of his birth becomes his native land. Therefore, a 'foreign' or 'native' land is but only a relative term in the sense that one has to remain detached from his native land when one has to answer the call of duty. The Indian soldier and his comrades-in-arms including his British allies in the poem are good examples of such persons performing their duty in the alien land, Africa. Some of them are not fated to reach their own country but would die in another man's land. Nevertheless, the land on which they sacrifice their lives for a great and common cause, gets to be their home while the land that was their home now ceases to be the same. Their great action would bring its own reward though they would not know of it 'until the judgement after death.'
Another salient theme of the poem is the doctrine of Karma. Through the selfless action of the Indian soldier and his likes in Africa, the philosophy of the Bhagavad-Gita is echoed that - "To action alone has thou a right and never at all to its fruits; let not the fruits of actions be thy motive; neither let there be in thee any attachment to inaction". T.S. Eliot says in the last line of the third stanza that wherever he dies bravely that soil is his. It occurs to the poet that the soldiers of different countries fighting for a common objective may not know the outcome of their strivings. Nevertheless, this possibility does not diminish the worth of their sacrifice. They become immortal as they are glorified in the memory of their people through their sublime act. The judgement after death shows the poet's preoccupation with the Christian doctrine 'of the last judgement' as mentioned in the Old Testament.

This poem deals with the idea enshrined in the Bhagwad Gita that it is sufficient to do one's action regardless of reward. Action in itself is significant whether we know its usefulness or not, it is possible we may know it only after death when God will deliver judgement on our actions, whether right or wrong.
Addressing the dead Indian, the poet says a man's destination is his own country, village, home, family. He is sisitting at his door in the evening & watching his grsndson playing with his friend in the dust. In other words, his destination lies in enjoying the charms of life connected with his own homeland.
If his destiny leads him away from his homeland then its memories continue to haunt him & crop up when he sits in convesation with foreigners, alien to each other. All these foreigners, haunted by memories of homeland, forge strange kinship.
Wherever man's destiny may lead him, the adopted land cannot be his destination, i.e. where he yearns to be. The land where a man dies bravely, struggling with his destiny, is his homeland. This fact needs to be remembered by his village, his family.
The poet, in emphatic terms, tells the dead Indian that Africa was neither his homeland nor was it theirs(Whitemen's--The colonisers who went to Africa for a "cause"). He died & was buried in the same graveyard as others'. Those who return home should carry with them the story of his "action" which was useful, even though its usefulness was not known, and its reward would be known only on the "Judgement Day".