Fortifications persist by adapting to offensive technology

Will future invasions still face fortifications, perhaps supported by drones?

Yes; fortifications evolve as offensive technology improves, and future defences may combine hardened positions with new materials, protection systems, and unmanned support.

The forecast expects future invasions to encounter fortifications because the contest between offence and defence is cyclical rather than final. When a new weapon defeats an existing wall or armour scheme, defenders eventually change materials, geometry, concealment, depth, or tactics. Future positions could incorporate advanced materials, active or electromagnetic protection, and combat-support drones. Those examples are explicitly forward-looking possibilities, not descriptions of a settled technology. The durable lesson is that forces still need to solve the operational problem of breaking or bypassing defended ground.