How does a naval blockade attempt to weaken an enemy during war?

A naval blockade attempts to weaken an enemy by preventing the ingress and egress of vessels to or from a defined part of the enemy's coast or territory. By restricting maritime access, a blockade serves as a tool of warfare in two primary ways:12

• Military Blockade: This is undertaken to achieve specific tactical objectives, such as the capture of a naval port.12
• Commercial Blockade: This is designed to force an enemy to surrender or negotiate by cutting off all commercial intercourse by sea. By severing trade routes, a belligerent aims to deprive the enemy of essential resources, including war matériel and economic supplies, thereby undermining their capacity to sustain the war effort.123

To be legally binding and effective, a blockade must be duly established by a government, maintained by sufficient naval forces to truly prevent access, and enforced impartially. Historically, while traditional blockades required warships to be stationed near the coast, modern advancements like submarines and aircraft have led to the acceptance of long-range blockades, provided they remain effective at preventing passage.1234