I agree with the statement because the sanction were ineffective due to lack of support. If they have a strong support on the issue of sanctions over Italy so the League in Abyssinia was not failed and got success over this matter. So we can say that ineffective sanctions were the main reason for the failure of the League in Abyssinia.
If the friend trusts you, understands you, cares for you, and is always(like always by your side when you need help), then they are a very true friend...