The recent blockage of the Suez Canal by the container ship Ever Given is a reminder of the importance of maritime choke points as they concern international commerce and national security. Choke points are primarily the effect of natural geography, which is one of the critical dimensions of strategy. In some cases, however, human agency, especially technology, can affect the strategic importance of natural geographic features and relationships. The shift from sail to steam, then from coal to oil-fired ships. From roads to railways. From horses to internal combustion engines. From the ground to the skies — aircraft to ballistic missiles, to drones, and hypersonic vehicles. Another human agency is the construction of canals in a way that significantly alters the geopolitical terrain.
Writing in the early 17th century, when much of Europe was in turmoil, Grotius sought to identify principles of law that might offer a peaceful basis for resolving and preventing wars. His three-volume book, first published in 1625 and dedicated to Grotius' patron at the time, Louis XIII, is regarded as the foundation of modern international law. In The Law of War and Peace, Grotius developed a system of principles of natural law, which are held to be binding on all people and nations regardless of local customs.