In the 1930s Germany under Adolf Hitler was strengthening
itself.
Britain supported this move because they wanted a strong Germany
to act as a bulwark to counter the Soviet Union.
Later in 1936, certain figures in the British political elite
came up with a strategy to push Nazi Germany eastwards into a war
with the Soviet Union.
They wanted to instigate a war of mutual annihilation between
Nazi Germany and Soviet Russia.
There is a lot of evidence that shows this.
Historian Carroll Quigley has a narrative on the events:
This event of March 1936, by which Hitler
remilitarized the Rhineland, was the most crucial event in the
whole history of appeasement.
So long as the territory west of the Rhine and a strip fifty
kilometers wide on the east bank of the river were demilitarized,
as provided in the Treaty of Versailles and the Locarno Pacts,
Hitler would never have dared to move against Austria,
Czechoslovakia, and Poland.
He would not have dared because, with western
Germany unfortified and denuded of German soldiers, France could
have easily driven into the Ruhr industrial area and crippled
Germany so that it would be impossible to go
eastward.
And by this date, certain members of the Milner
Group and of the British Conservative government had reached the
fantastic idea that they could kill two birds with one stone by
setting Germany and Russia against one another in Eastern
Europe.
In this way they felt that the two enemies would stalemate
one another, or that Germany would become satisfied with the oil of
Rumania and the wheat of the Ukraine. It never occurred to
anyone in a responsible position that Germany and Russia might make
common cause, even temporarily, against the West. Even less
did it occur to them that Russia might beat Germany and thus open
all Central Europe to Bolshevism.
http://yamaguchy.netfirms.com/cikkek/anglo_12b.html
...Any analysis of the motivations of Britain in 1938-1939
is bound to be difficult because different people had different
motives, motives changed in the course of time, the motives of the
government were clearly not the same as the motives of the people,
and in no country has secrecy and anonymity been carried so far or
been so well preserved as in Britain.
In general, motives become vaguer and less secret as we move
our attention from the innermost circles of the government outward.
As if we were looking at the layers of an onion, we may discern
four points of view:
(1) the anti-Bolsheviks at the
center,
(2) the "three-bloc-world" supporters close to the
center,
(3) the supporters of "appeasement," and
(4) the "peace at any price" group in a peripheral
position.
The "anti-Bolsheviks," who were also anti-French,
were extremely important from 1919 to 1926, but then decreased to
little more than a lunatic fringe, rising again in numbers and
influence after 1934 to dominate the real policy of the government
in 1939.
In the earlier period the chief figures in this group were
Lord Curzon, Lord D'Abernon, and General Smuts. They did what they
could to destroy reparations, permit German rearmament, and tear
down what they called "French militarism."
...The anti-Bolsheviks, including D'Abernon, Smuts, Sir John
Simon, and H. A. L. Fisher (Warden of All Souls College),
were willing to go to any extreme to tear down France and
build up Germany.
Their point of view can be found in many places, and most
emphatically in a letter of August I l, 1920, from D'Abernon to Sir
Maurice (later Lord) Hankey, a prot้g้ of Lord Esher who wielded
great influence in the inter-war period as secretary to the Cabinet
and secretary to almost every international conference on
reparations from Genoa (1922) to Lausanne (1932).
D'Abernon advocated a secret alliance of Britain
"with the German military leaders in cooperating against the
Soviet."
http://real-world-news.org/bk-quigley/12.html#42
http://en.wikipedia.org/wiki/Appeasement_of_Hitler
Most english history books discussing the origins of WWII tend
to push a propagandist version of Britain's role in it and cover up
the facts.