Answer
Wa `alaykum as-Salamu wa Rahmatullahi wa Barakatuh.
In the Name of Allah, Most Gracious, Most Merciful.
All praise and thanks are due to Allah, and peace and blessings be upon His Messenger.
In this fatwa:
1- Islam permits the increase in capital through trade.
2- At the same time, it blocks the way for anyone who tries to increase their capital through lending on the basis of usury or interest.
In his response to your question, Prof. Dr. Monzer Kahf, Professor of Islamic Finance and Economics at Qatar Faculty of Islamic Studies, states:
While a few verses talk about taking riba, there are others that talk about riba in general, like:
“…but Allah has permitted trading and forbidden riba” (Al-Baqarah 2:275),
“Allah has blighted riba and made almsgiving fruitful” (Al-Baqarah 2:276),
“O you who believe, observe your duty to Allah and give up what remains (due to you) from riba, if ye are (in truth) believers. And if you do not, then be warned of war (against you) from Allah and His Messenger. And if you repent, then you will have your capital (without interest). Neither will you make (the debtor) suffer loss, nor will you be made to suffer loss.” (Al-Baqarah 2:278–279) (Al-Baqarah 2:278)
Of course, taking riba is the main reason behind forbidding it, and there is no circumstance where taking riba may be permitted.
On the other hand, there may be circumstances that make giving it necessary. This implies that taking it is pure injustice, while giving it may be justified by necessity.
Anyway, we know that riba cannot be taken if there are no persons who give it, and this is why our Prophet Muhammad (peace and blessings be upon him) informed us that the wrath of Allah is on the taker, the giver, the writer, and the two witnesses.
In another version of this hadith, the Prophet said that those persons are all alike with regard to the wrath of Allah because for the riba to take place, a giver, a taker, a writer, and witnesses are needed.
Allah Almighty knows best.