Pingback introduced back-linking websites practically forming a network in 2002.
URLs are a form of linking content, forming a network. Although uni-directional (into one direction only).
Some platforms integrate into websites and form a form of meta-network of their content or accounts.
Most recently and popular, the AT Protocol is an alternative generic protocol similar to the fediverse, powering Bluesky.
Professional army.
Support and train a reserve army of those willing. Citizens that could support the country and other citizens in the case of an invasion. Some countries do that. I like to think of those.
Only if otherwise necessary general service. E.g. active invasion you can’t otherwise oppose, or you can’t establish a minimum reserve.