What invention of the 1900s might have lessened gibraltar's importance as a military base?

Improvement in Naval operations ( development of better Naval ships )

Step-by-step explanation:

Gibraltar is known for its strategic location in Europe between Spain and the united kingdom. its mountainous kind of structure which was developed by royal engineers makes Gibraltar a good base for military activities in the Mediterranean. because of its structure it had proper harbors and runways which was some of the reasons the British Armed forces and the royal navy saw and used Gibraltar as an important military base for more 200 years.

this was because the British military could observe the shipping channels for the safe anchoring of these ships,

the importance reduced with the invention of better Naval ships which could sail for a farther distance than before.

step-by-step explanation:

(s)he  is right it would be 5.5% because it is smaller than 15.5% or anything smaller than 15.5% in general