Brew strength

So it looks like my latest brew is going to turn out very thin and weak. No problem - I'll just be bloated before I'm drunk

My plan up until recently with my next brew was to do a stonkingly strong trappist ale so I figure it's wise to find one thing out...

What effects the strength of the brew. Obviously on a basic level it's the yeast converting sugar to alcohol but why, for example, has my latest brew come up more like a 2% instead of 5? What can i do to jack up the strength of future brews ets? Just generally speaking...

More sugars for the yeast to convert. However this does not mean table sugar or simple sugar either more extract or more grains to provide more sugars.

and then more hops to even out the extra sugars

Are you certain its only 2% ? Mash or liquid malt extract.

Post a cliff note of your recipe and process.