The United States government's refusal to supply arms placed the Israeli government in a serious situation. Israel was heavily dependent on the outside world for war material, since the Suez campaign had done nothing to decrease the danger it faced from its Arab neighbours. For Ben-Gurion to exploit the only remaining source, the Federal Republic, was a bold step, fraught with great political danger to his coalition government. The dialogue between the Federal Republic and Israel over weapons began in 1957. Israel, whose defence expenditure per capita was the highest in the world, desperately needed arms and lacked the funds to purchase them. They still resented any relations with Germany and would have found the sale of arms to that country particularly obnoxious. Strauss reports on his interest and that of his ministry in the co-operation between Israeli tanks and the Israeli air force during the Suez campaign as well as in captured Soviet war material.