Explanation:

- A contract entered during war with an "alien friend" means a contract with a person who is a national of a country not at war with your nation.

- Such contracts are generally valid because there's no legal prohibition; alien friends enjoy similar trading and contract rights as citizens, unless specifically restricted by law.

- Option 1: Ineffective – Incorrect. The contract is not automatically ineffective.

- Option 2: Valid – Correct. Contracts with alien friends during war are valid in most cases.

- Option 3: Voidable – Incorrect. The contract is not subject to being set aside at the option of any party, unless some other legal ground exists.

- Option 4: Void-ab-initio – Incorrect. These contracts are not void from the outset due to war.