Without much hesitation, Wilhelm I agreed to the plan. Prussia's resources were limited, and there were no valuable chips to be traded with. Now that they were issuing promissory notes, why not inflate the figures a bit?
The international situation was ever-changing. Just a few years ago, England and France were fully supporting Prussia in its resistance against Russia, but in the blink of an eye, they were looking to ease relations with the Russians.
It wasn't that Wilhelm I didn't want to stop all this from happening; it was simply that he couldn't, not in the face of interests.
The already declining Russian Empire was no longer a competitor of England and France, so they could naturally play nicely together.
During the next Prusso-Russian war, even if England and France were to stand on their side, the level of support wouldn't be as substantial as the last time. To win the war, they could only rely on their own efforts.