When the Balloon Goes Up

This one has really got me puzzled. I am aware of the Archimedes Principle & can see how it applies to liquids, but I cannot see how it accounts for, say,

a helium-filled balloon rising. Such a balloon still has mass & will accelerate upwards when released. If a mass accelerates, a force must be acting on it. My question is: where does this force come from? I await the deluge of suggestions (sensible or silly).

Buoyancy

https://en.wikipedia.org/wiki/Buoyancy

Magic pixie dust, it's the only explanation that works

This one has really got me puzzled. I am aware of the Archimedes Principle & can see how it applies to liquids, but I cannot see how it accounts for, say,

a helium-filled balloon rising. Such a balloon still has mass & will accelerate upwards when released. If a mass accelerates, a force must be acting on it. My question is: where does this forcecome from? I await the deluge of suggestions.

As a Jedi Knight of the Force, I cannot divulge where my powers come from.

Angel1.