Britain's main strategy had, for a long time, been a strategy of "balance of power."  This means that the British did not want any one country on the continent of Europe to get too strong.   That way, no country could become a huge threat to Britain.

This is why Britain wanted a stronger Germany.  They did not want France or, especially, the Soviet Union, to become so strong that they would be able to threaten Britain's power.  Of course, this kind of backfired because Germany got really strong and France and Russia did not get strong enough to balance Germany.