When a man is jealous, does it mean he loves?

Many men believe that jealousy is proof of their feelings. But more often, it's simply a fear of losing power. A woman who is confident doesn't arouse jealousy—she arouses a desire to retain attention. And the difference is huge.
I've noticed how men are jealous not because they're hurt, but because they don't like the realization that they're not the center of the universe.
But here's the paradox: sometimes a little jealousy can ignite a spark, restore a taste for the relationship, and awaken passion. The main thing is not to weaponize it.
So where is the line? Between "I care" and "I don't trust you"?