PARIS / ROME – A “grain pact” to allow Ukrainian cargo to transit beyond the Russian naval blockade in the Black Sea and avoid the “food tsunami” feared by the United Nations: this is the goal of the diplomatic canvas, in these hours. An ambitious challenge, but hanging by a thread and subject to many unknowns. The role of the United Nations, a possible guarantor of the agreement, ends up at the center of Macron and Scholz’s phone call with Vladimir Putin.