ISRAEL's  prime minister has declared that his country is prepared to ratify a treaty banning nuclear tests, a senior UN official has said. Lassina Zerbo, who heads the UN organisation created to implement the treaty, said Benjamin Netanyahu considers the issue of ratifying the treaty a matter of "when, rather than if". Israeli ratification would move the treaty closer to taking effect, leaving only seven of the 44 countries that must ratify it for the pact to go into effect. Mr Zerbo, who heads the Vienna-based Comprehensive Test Ban Treaty Organisation (CTBTO), [...]