Before the start of the Second World War, British armored doctrine was
in a terrible muddle. Opinion had been divided between the proponents of
the tank who saw it as the weapon of break-in, using it as an infantry
support weapon, and those who saw it as the weapon of breakout, using it
to restore mobility and to destroy the enemy's forces behind the
frontline. In many ways it was a division between those who saw the tank
solely through the prism of the experience of the First World War, and
those who saw it a decisive weapon for the future. Britain was also
conscious of the continuing requirements for imperial policing, in which
small tanks and armored cars had already proved their worth. As a
consequence, it was decided that Britain needed three different classes
of tanks: Light tanks for the policing role that could also be used for
reconnaissance duties in a general war, fast and lightly armored Cruiser
tanks for breakout and exploitation, and heavily armored but slow
Infantry tanks for the break-in.