The Great Machine returning Draal's youth of 30 years' prior is used to explain the casting of John Schuck to replace Louis Turenne, who was unavailable to reprise the role.
Lord Refa's curt dismissal of treaties forbidding the use of mass-drivers as "ink on a page," has a historical parallel of when Germany invaded Belgium at the beginning of World War I in 1914 in direct violation of the Treaty of London of 1839. When the Ambassador of Britain warned German Chancellor Theobald von Bethmann Hollweg that Britain would go to war in response, the Chancellor dismissed the treaty as a "scrap of paper."
The U.S. Navy has tested a mass-driver railgun that accelerates a 7 pound projectile to seven times the speed of sound.
Lord Refa says to Londo that the Centauri will be using mass-drivers to attack Narn. In point of fact, their ships are armed with railguns. A railgun is a purely electrical gun that accelerates a conductive projectile along a pair of metal rails using the same principles as the homopolar motor. Railguns use two sliding or rolling contacts that permit a large electric current to pass through the projectile. This current interacts with the strong magnetic fields generated by the rails and this accelerates the projectile. When the ships approach Narn look closely at the undercarriage of the Centauri ship, and you can see the electrical charge surrounding the projectile between the two rails.
This takes place from December 3 to December 10, 2259.