Is "All risks and war risks " it always needed in all cases?

better safe than sorry

Yes.

usually all risks covers ship capsizing,damage to goods,etc.The war risk clause is an additional endorsement to the policy that covers the insured(buyer).The war risk clause covers the policy holder(buyer and buyers bank if it is a transaction through an L/C)) that in the event of a war which damages/destroys the goods while in transit,the insurance company has indemnified the policy holder.It is always better to have an all risk insurance policy which also has an endorsement of war risk inspite of the fact that it carries a slightly higher premium.

you have to take risk when you see a good opportunity. Without risk you will never get anywhere in life. Sometimes risk worth millions