Editor's Note: This is the first of a two-part series on the unfolding consequences of Iran's weakened regional position following its 12-day war with Israel. For the first time in decades, Iran finds itself on the back foot of a changing regional order, led by Israel's government under Prime Minister Benjamin Netanyahu, with the support of the United States under President Donald Trump . The 12-day war launched by Israel took Iran's government and its military by surprise since it occurred while Tehran and Washington were engaged in nuclear talks. With the conflict now paused by a fragile ceasefire , Iran's strategic trajectory is set to enter a period marked by diminished regional influence and reduced capacity for power projection. The 12-day war significantly degraded Iran's capabilities through personnel losses and damage to critical infrastructure and military assets, particularly its ballistic missile arsenal.