Hi /r/AskHistorians, Czechia often also known as the Czech Republic. At least there is a big similarity. It is a bit controversial topic in the Czech Republic for last few years. I would like to know more about it in depth.

In March 1939, soon after the unilateral annexation of the remnants of Czechoslovakia, the UK and Poland signed a guarantee to the independence of Poland. When Germany invaded Poland in September the Allies, though, did nothing to stop Hitler; did they really want to stop Hitler or declared war mainly because of treaty obligations? To further specify my question: would have the Western Allies intervened if in March Poland had not signed the guarantee or if it was invaded instead of Czechoslovakia?

With the recent annoucement about Saudi Arabia now allowing movie theaters, I was wondering.. how common were movie theaters 35-40 years ago? What movies did they show? What led up to their banning?

Like the title says. I'm interested in knowing if there are nations out there, that supported Rhodesian unilateral declaration of independence? Were some nations split, like the people supported the independence but the government didn't?

I am interested mostly in the decision making processes of pre-WWI armies in the adoption of camouflage, and what methods they used to test its effectiveness, but data from other time periods related to camouflage effectiveness is welcome. For example, was there a dramatic reduction in casualties with the adoption of new uniforms, and to what percentage?

I'm also interested in why certain armies chose certain colours, what environments they expected to fight in, functionality (like allowing for hot weather), and cultural considerations to the uniforms of WWI.

Thank you.

Otto von Bismarck allegedly quipped "I am firmly convinced that Spain is the strongest country of the world. Century after century trying to destroy herself and still no success."

While Spain was no superpower in the 19th century, certainly it wasn't the only country with issues, so did Bismarck really single the Spanish out and, if so, why? Even in the 19th century context, I would even suggest France is politically better suited to for this claim.

In his book Destiny Disrupted: A History of the World Through Islamic Eyes, Tamim Ansary makes the claim that in terms of complexity, the Ottoman Empire was comparable to modern-day America. I have always been fascinated by the Ottoman Empire, especially the millet system and the devshirme, but I don't know nearly as much as I should about how the Ottoman Empire actually operated.

Accusations of Environmental Determinism have plagued this book since it's publication. I read it a long time ago without some of what I know now and I still found it hopelessly biased. It seems to ignore huge parts of human innovation vis a vis agriculture. Not to mention acknowledging state creation in this phase of capital accumulation. What are your professional opinions in regard Mr.Diamond book?

Edit: added a word in the last sentence.

I've been doing some research on the use of urban gang and mob violence as a political tool during the late Roman Republic (about 140–40) and was curious if there are any contemporary sources that justify or explain the violence. Some of the main figures to use urban violence for political ends include the Gracchi, Saturninus, Drusus, Catiline, and most famously Clodius and Milo (roughly in chronological order). From what I can tell, urban political violence was mostly carried out by populares senators but especially by the tribunes of the plebs. There are many texts (mostly Cicero) justifying the use of violence against these men, but I haven't come across any that justify the use of violence by them.

Did they say it was a Civil War, an insurrection, or did they just call it a revolution?

Iran has been ruled by Turkic dynasties for most of the last thousand years, but despite scattered pockets of Turkic languages elsewhere, only in the northwest did the majority of the population switch to using Turkish.

When did Azerbaijan (the historical region, not just the republic) come to be majority Turkish speaking? What factors would have contributed to this one region of Iran being the only one to adopt Turkish?

Contrary to how my post may imply, I know that crossbows are first documented in China. I did not mean to appear like I believe they came from Europe and were exported to China. What I mean is that there just seems to be so much information available on European crossbow design, but very little on the Chinese variants.

I understand comparing religious movements is never exact, but are they similar ultra-conservative groups?

Title says it all, I find it hard to believe, but is she right?