Complex sentence: Mohammed Al Khalifa attempted to negotiate a protective treaty with the British to halt Faisal's advances and was initially unsuccessful in doing so, but the British reconsidered their position after an intelligence report and situated a naval blockade in Manama.
Split into simpler sentences: Mohammed Al Khalifa tried to negotiate a protectorate treaty with the British to halt Faisal's advances but was unsuccessful. The British reconsidered their position after an intelligence report and situated a naval blockade in Manama.