Your definition of "complete dominance" is different from most people's.
If you completely dominate your enemy, you prevent them from being able to affect the situation. Iran is maintaining a blockade over a major shipping lane that the USA does not want them to. The USA's inability to prevent this shows that they are not "completely dominating" Iran.
If you completely dominate your enemy, you prevent them from being able to affect the situation. Iran is maintaining a blockade over a major shipping lane that the USA does not want them to. The USA's inability to prevent this shows that they are not "completely dominating" Iran.