As all good stories give the protagonist an external goal, so must he/she also have external conflicts.
The external conflict is the force or the situation that tries to keep the protag from reaching his/her desired goal. There can more than one. In fact, the presence of many can make the story more riveting and can cause the reader to wonder how the protagonist will ever survive.
The strength of the the external conflict may depend on the genre you're writing. I would think in a thriller that the conflict and goal would loom throughout the entire story, whereas in a romance it might be overshadowed by the internal conflict.
Ironically, the external conflict for your protagonist might be the antagonist's external goal. Or in a romance, what the hero wants is what the heroine is fighting against.
For example, in my WIP my tattooed ex-bartender wants to buy land for a non-profit project. She finds the perfect piece owned by a fellow churchmember who happens to disapprove of her in every way.
Is that a strong enough external conflict? I'm not sure yet. I have to write it out and see where it takes me.
What kind of external conflicts have you come up with in your writing? Do you feel that this is a strong or weak point for you?