The United States deployed 5,000 Marines to the Middle East, likely intending to escort convoys or seize some coastal control points, or more aggressively, to capture islands.

For Iran, with a population of nearly 100 million and 610,000 soldiers, it's also a theocratic state with temporary mobilization capabilities.

It's unlikely the US would attempt to occupy Iran, and even capturing islands would actually be a sign of escalation in the conflict.

The duration of war could potentially be longer than expected.