Failing to fast four Ramadaans during war and becoming too old to make up for them

Question: My grandfather is 88 years old; he was born in 1907. He witnessed the war waged by the Algerians in 1954 to gain liberation from the French colonization. At that time, he was a soldier in the ranks of the National Liberation Army. Due to war, the soldiers had to abstain from Fast during four months of Ramadaan when they were in a state of war. My grandfather was not the only one who did so, but rather all the soldiers did. Now he is 88 years old as mentioned above, and he did not make up for any of the days of these four months of Ramadan. The questions are:

1. Can my grandfather pay Kaffaarah (expiation) in compensation as he is aged and cannot endure Fast?
2. If your answer is in the affirmative, how much should he pay in Algerian dinars as compensation for these months, and to whom should he pay?
3. Can he pay the Kaffaarah for the month of Ramadaan in this year?

Answer: If your grandfather is actually unable to make up the four months of Ramadaan he did not fast, then he has to feed a needy person an amount of 1.5 kg of the country’s staple food for each day he failed to fast. Giving money does not serve as a substitute for providing food. The Kaffaarah for the four months can be given at once to some poor families. He should repent for this delay in making up for the missed days of Fast… read more here.