just to add a bit to what others have posted:

you can often even the odds with a military station if it's clear where you will be attacked.

Ex: if you are facing an 10 k enemy fleet and you only have 7k, build a military station with an ftl snare right next to the starbase in the system closest to the enemy and position your fleet close by.

They will highly likely attack that system first and then have to face the combined power of your starbase (usually ~2k or so) military station (usually 1-6k depending on the tier you have unlocked), and your 7 k fleet.

If you have any intel on the enemy and your fleet is geared to counter theirs, you should definitely win that engagement and from there they are at your mercy.