This was the US way of buying world influence. We can hardly blame Japan for saying “yes, gracious Master” to something like this.
Yes, it's how we bought post-war influence.
But the USA is MOST influential when the entire world knows we'll seek OUR interests above all others, and unilaterally if necessary.
Right now our allies see us as patsies and bullies. Making them pay their own way is likely to reverse that dynamic.
As for blaming Japan: Hell yes we can, and reasonably so.
From about 1965 onward, 20 years after the war, they have been CAPABLE of defending themselves against all comers.
They chose to rely on Uncle Sugar...and have been hating him ever since.