Numerically, our armed forces are "small", as in boots on the ground, cos the likely hood of a WW2 type encounter is unlikely. Intelligence IS defence; cyber, hacking, stuff I have no idea about, and there is a big doughnut shaped building in Cheltenham stuffed full of nerds, linguists etc who do that pretty well.
The RN is helping to keep oil tankers safe in the Gulf as we speak, (not just Brit ones). Russian aircraft challenge our air space frequently, so the RAF get them to go away; ergo, Vlad knows we are defending, if needed. And more importantly, know they are coming.