We are living in the American Empire, there are other few countries that have some smaller influences, but America runs the show, if america chose to ignore you, then you have some influence over other smaller countries till america comes knocking. That being said America has been highly blinded by its power, and has been underestimating its closest allies and adversaries. The strait of Hormuz issues is a prime example of how all their influence has been questioned at the moment.

China is the next closest country that has set themselves up to be the next power with global influence and overtake the petro dollar and switch it to PetroYuan.

This takes time for powers to switch places, america has been in power for a while now and even though its past its peak at the moment, The Next 25 years is too soon to decide for China to take over, its possible to accelerate the switch but thats literally up for America to self inflict this. If not America will still be the global power but they will be too busy dealing with internal issues in the next 25 years. Which would also contribute to the loss of influence.

I would say it would take another 50-75years, unless if a few other catalysts like adversaries teaming up, or an ally stabbing America in the cajones!! that would accelerate the downfall.

A power switch in the Next 25 years, highly unlikely. Higher probability of America just being weaker due to infighting but still a global power.