Infantry guns are not going to come back because shoulder-launched grenade weapons such as the M4 Carl Gustaf recoilless rifle and anti-tank guided missile launchers are used as direct fire infantry guns, and 120 mm mortars already began replacing infantry guns in the indirect fire role as early as in 1943 due to lower costs and greater effect.
|The new M4 Carl Gustaf is finally - after almost 70 years - not terribly heavy any more.|
|first transport glider used in combat: DFS 230|
Transport gliders won't come back ... because they already did in the form of self-steering cargo glide parachutes. There was even a hang glider-like transport glider prototype approx 15-20 years ago, but the collapsible wing principle of parafoils was even better.
Tethered observation balloons
Tethered observation balloons allowed for visual detection of artillery batteries and other targets, and observation (thus also correction) of artillery fires. They were common during the First World War's trench fighting and already uncommon by the early Second World War. Artillery observation planes were expected to replace them during the Interwar Years, but they were largely a failure. Instead, STOL liaison aircraft such as Fi 156 and L-2 were occasionally used, if circumstances permitted their employment.
The huge advantage of tethered systems over free-flying aerial drones is that you don't need the hardly reliable radio link. The use of a tethered observation drone at 150 m while the platform vehicle is moving does almost immunise against counterfires. You would need a fibre optic guided artillery missile to hit the vehicle on the move.