Iran Closes Strait of Hormuz as Trump Halts Tehran Talks

Geopolitical tensions escalated on August 19, 2026, as the Government of Iran closed the Strait of Hormuz following a projectile strike on a bulk carrier in the waterway. Iranian Chief of Staff Ali Abdollahi warned Gulf states that assisting the U.S. military would be viewed as active participation in the conflict. This followed reports that Iran was preparing to strike U.S. military bases in Bulgaria and Cyprus, as well as submarine fiber-optic cables.

In response to the instability, Donald Trump ordered a halt to diplomatic talks with Tehran, shifting U.S. strategy toward severe sanctions and increased economic pressure. Trump further intensified the situation by declaring the Strait of Hormuz to be United States territory. To manage long-term borrowing costs amid the volatility, Treasury Secretary Scott Bessent announced plans to double the buyback program of 30-year Treasuries to $4 billion.

Financial markets reacted with volatility. The FTSE 100 ended the session slightly higher at 10,743.35, supported by energy giants like BP and Shell as oil prices remained above $91 a barrel. However, the index faced pressure from new data showing UK inflation rose to 2.9% in July. In corporate news, Trainline shares fell 14% due to a Competition and Markets Authority probe into drip pricing, and Smith & Nephew shares declined following the immediate resignation of CFO John Rogers.