That isn't obvious to me.
What seems more plausible to me is that Ramsay MacDonald isn't Prime Minister of Great Britain and Herbert Hoover isn't President of the United States and that the holders of those posts in 1930 aren't as favour of disarmament and are prepared to put John Maynard Keynes theories into practice. It will also help if the UK and US Treasuries, Parliament, Congress and both countries electorates
ITTL France and Italy might sign the 1930 London Naval Treaty because they would be allowed more cruisers under the 5:5:3:1.75:1.75 ratio.
Another possibility to be sure. Who the PM and POUS are is up for grabs.