Lean is not Agile, is it?

We live in a time where project management Methods exist in abundance and traditional methods compete with Agile (with a capital A) and lean approaches which in turn compete with each other.
But do they? First of all methods hardly ever compete - it's people who do the competing. The approaches just exist and either oppose each other, complement each other or have no relationship whatsoever. The Agile movement mostly was a counter-movement against the overly structured approaches to software development that came to live in the 1980s and basically this movement re-instantiated good practices from the 1950s and 1960s as for example Craig Larman points out in his article Iterative and Incremental Development: A Brief History.
The whole lean approach in turn surfaced as the Agile movement was taken over by the same people who enforced the rigorous methods of the 1980s and more and more problems in the value chain, but outside the core development efforts, became visible. David Anderson – one of the fathers of Software Kanban – calls Kanban (which is related to lean software development) a "post-agile" approach, which doesn't really help in differentiating Agile and lean but emphasizes the fact that they are not the same.
From my experience companies that focus on agile have highly productive teams but often lack an efficient flow across the value stream while companies focusing on lean tend to have a real efficient flow but tend to lack efficiency inside the teams. To employ agile techniques inside the stations along the value stream while managing the value stream itself in a lean manner to me seams to produce the best results.
To get a first hand experience of how to integrate lean and Agile approaches you might want to come to the workshop that Tom Breur and I will run on May 28th & 29th in the Netherlands