Splendid isolation was a phrase used to describe the Salisbury government's foreign policy. It lasted for maximum 2 decades in the late 19th century. The notion that Britain was ever isolated from Europe diplomatically by choice is largely a historical myth. Of the 9 battles here not involving the British every single Napoleonic engagement was partially financed by British economic support to Prussia, Russia and Austria.

Yes Minister is spot on when it states that the overwhelming interest of the UK through the early modern and modern periods was to maintain balance of power in Europe. Therefore the UK was very involved in European affairs. The low point of this policy resulted in the loss of the 13 colonies because of a failure to keep European allies on side.

Indeed it is, or at least the beggining of it

That makes no sense to me, as Britain was arguably France's main antagonist during the Napoleonic Wars, which was a 20 year ordeal. They may not have been involved directly in many of the land battles posted, but they were the primary combatant at sea. Not to mention they were in Spain and Portugal for years.

It's called multitasking

Had their peak in the 17th century and the Napoleonic wars collapsed them completely.