On 6 April 1927, marking the tenth anniversary of America's entry into the Great War, Briand made a statement to the Associated Press proposing a bilateral pact of perpetual peace between France and the United States. Positing that the two ‘great democratic nations’ were inspired by an ‘identity of aims’ in their peace policies, he declared that they should set an example to the world by signing a treaty committing both to ‘the renunciation of war as an instrument of national policy’. More than two months passed before Kellogg signalled, on 11 June, that the Coolidge administration was willing to ‘enter into diplomatic conversations’ about Briand's proposal. Ten days later, Washington received a formal note with the French draft treaty.

Thus, a complex process of transatlantic negotiations was set in motion, which went on for more than a year and evolved from ‘soundings’ between Paris and Washington to a series of ‘multilateral’ exchanges, which were largely steered by the US State Department. At its end, on 27 August 1928, the United States concluded, not a bilateral treaty with France but a multilateral pact signed not only by all Locarno powers and their European neighbours to the east (though the Soviet Union abstained) but also by Japan and a plethora of other states.

From the outset, Kellogg had suspected that Briand's plan amounted to ‘a defensive treaty with France’ that would allow Paris to buttress the postwar status quo and ‘leave it open to her to take what action she liked in Europe’ while ensuring Washington's ‘neutrality’.