Not giving the Czechs to Hitler would have meant war, because they didn't have enough collective force to make Hitler back down without one. Britain and France were absolutely terrified of another war, because the wounds from the last one weren't even close to healed. Between casualties and a huge drop in number of births, both countries had a million-man gap in their potential defenders compared to what they'd have had if Franz Ferdinand hadn't stopped a bullet in 1914. In retrospect, the First World War not only slew the German Empire, the Russian Empire, the Ottoman Empire, and the Austro-Hungarian Empire, it probably also mortally wounded the British Empire. The prospect of Round 2 absolutely terrified both countries.
Paul F. Kennedy writes a lot about the decline of the British Empire in relative and absolute terms around this period. I recall him talking about how in the moment, there was no public or elite perception that the British Empire was irrevocably doomed to failure post WWI, and plenty causes for celebration. The timeline he sets out is:
-Post napoleonic wars, the UK is really in an extraordinary position where it has no expensive long term continental commitments. Its chief rivals of Spain and France have lost their navies. All the major powers like Prussia, Austria, Russia are still dealing with damage inflicted by France, whilst France herself is exhausted. The same navy which protected it, also becomes the tool for exerting imperial power abroad at no extra cost. This allows British merchants to gain preferential access to foreign markets overseas, even in places like South America, ostensibly under Spanish control.
-The industrial revolution kicks off in the UK, providing insane advantages for the UK economy over the rest of the world. This + the naval power + the UK's rivals still climbing out of the gutter allows for the UK to capture three quarters of the world's markets. But it stands to reason that if industrialisation could unlock the full potential of the British economy, then those countries with greater landmasses more restricted by their size like Germany, Russia and most of all - the USA, would benefit the most from those restrictions being lifted. Which inevitably is what happens
-1900s start coming around and the world is looking mighty different. Where before the British had control of 3/4s the world's markets with an obligation to defend next to none of it versus rivals who couldn't really challenge it, the British had control of 1/4 the world's markets with an obligation to defend all of it - against powers that were reaching their full industrial potential like France, Russia, Japan, Germany and USA. The Japanese destruction of the Russian navy did assuage fears somewhat, (but Canberra and Washington will later lobby for Westminster to gut the Anglo-Japanese alliance).
The requirement to defend more with less, whilst it became more and more expensive to field cutting edge war machines, inevitably meant something had to give. This leads to Britain being forced out of "splendid isolation" and their attempts to ally with the USA, Japan, and Italy - and even for the time, it stunned the German high command that the UK seirously honoured their alliances with their long time enemies/rivals France and Russia.
-By the eve of WWI, the British Empire's economy was already in a tough pinch. Lots of the British Empire's former export markets like South America were being dominated by American goods. A lot of the British Empire's own colonies were dominated by American goods. Even the British Isles were seeing UK companies outcompeted by American goods. Not just American goods too; whether German chemicals or American machines, British companies were being outcompeted by foreign companies using more modern plant and in larger scale.
Most of the world's empires adopting protectionist barriers whilst the UK still ruggedly clinged to free market ideology meant British goods were being priced out of rival European colonial empires and spheres of influence, burdening their ability to maintain the naval power that guaranteed the security of the Empire.
-This did not alarm British business elites, because for the most part they had made the transition from an industrial capitalist mindset, to a purely capitalist mindset. They did not fear American or German factories - they funded them. Any chance to outsource to cheaper labour abroad was a big W for them. London became a gigantic centre for global finance, insurance, law and banking. You get a lot of celebratory missives written by finance people huffing their own farts and gushing about how they have discovered a new form of wealth, whilst quietly deindustrialising themselves and industrialising others.
-WWI breaks out. Directly, the war traumatises the public, raises nationalism in overseas colonies through the roof (having already lost Ireland), indebts the government to JP Morgan, wipes out their wealth reserves and all the overseas investments made and lost. Indirectly, the British Empire more than any of the global powers depended on globalisation. So the world's economies being in a state of disarray also wrought ruin to the British Empire's economy.
-Post WWI it still doesn't look
that bad because, yeah the British Empire is suffering, but so is everyone in the world. But shit is totally fucked, and only not obvious because the USA took the #1 spot but said "nah I'm gonna be isolationist c ya you can have the ball." UK gov becomes distinctly aware that of the Atlantic, Meditteranean, Indian and Pacific Oceans, they can afford to protect two and a half of those.
-WWII sees the UK give all of its technology, capital, gold and markets over to the USA, losing what remained of its competitive edges and resources. It manages to splutter on like a zombie until the USA pulls out life support in the Suez Crisis
-Fast forward to 2025 UK still in this bizarre place where it can produce people who invent crazy shit like the world wide web, plastic or microchip wafers and yet not actually capture much of that value chain in its own economy, preferring instead to outsource what little of its industry remains. Where it retains some great resource, it just sells it off to foreign hedge funds and state investment vehicles, selling off our land, our transport, our water. There is something distinctly ironic that we export nuclear reactor parts but have lost the skills base to actually build nuclear reactors after they privatised the state owned construction firms. A british engineer will make more money working for a taiwanese semiconductor corp than they would for a british one, doing the same job.
fully half of England is owned by 1% lmao -_-