Is the tenant entitled to claim back the advance rent paid for the second year, during which they were unable to use the property due to war and the damages it sustained, and who bears the costs of repairing these damages?

The basic principle is that a rental contract is binding on both parties, and it is not permissible to annul it if it was concluded validly. However, circumstances may arise that permit one of the parties to annul it, such as the disappearance of the reason for renting or the occurrence of general conditions that prevent benefit. The Hanafis have broadened the scope of excuses that permit the annulment of the contract, considering any circumstance that incapacitates the contracting party from proceeding with the terms of the contract except with excessive damage that was not warranted by the contract as an excuse. Examples include the tenant's bankruptcy or their compulsion to leave the country. The tenant has the right to annul the contract for the period during which they are unable to benefit from the property due to the events mentioned in the question, and the rent corresponding to that period shall be returned to them. The tenant is not liable for damages sustained by the property due due to these events unless they had a hand in them, because their possession is one of trust (yad amanah).