As I got it here after some hours of joining, It is not allowed to ask political questions though, it is very difficult to differ them from each other completely and in many cases they are melted together and you cannot divide them if you want to find your "actual problem" mentioned in your question. Is there any significant method to find which questions are political and you should avoid of them and vice versa? It can guide users to ask better questions and not face to closed or deleted questions.
Seems that your main question (from your comment) is can you ask questions that "your experts do not find it off topic by this pretext: It is political not historical?!".
Due to the fact that history and politics are frequently intertwined, it's hard to answer in general without seeing a specific question.
The rule of thumb would be:
If you need historical knowledge to answer a historical/political question (e.g. access to documents from Churchill administration, even if the question is about Churchill's politics) it may be best to ask on History.
It would ALSO be ontopic on Politics, but there's a better chance of a good answer here - more people here are likely to know how/where to access Churchill's archives than on Politics.
If the question is pure politics without the need for historical expertise/knowledge (e.g. what are details of this current law), then it is OFFtopic for History and should be asked on Politics.
If the question is dealing with politics but touches on history, it's NOT offtopic on either site. But again, one of the sites might be a better fit for any given specific question, depending on its exact historical quotient; even if it is on-topic on both.
Short version - you will be most at risk at being considered offtopic on History.SE if the question is purely political, and no historian or history enthusiast would possibly be interested in it from historical perspective.
Having said that, please realize that there's a difference between "offtopic for this site" - but ontopic for Politics - and "subjective question that does not belong on any SE site, because it can not be answered objectively, just discussed". This was covered in ihtkwot's answer in detail.
This question is best answered by what questions you should NOT ask. As the Frequently Asked Questions (FAQ) section says: "You should only ask practical, answerable questions based on actual problems that you face. Chatty, open-ended questions diminish the usefulness of our site and push other questions off the front page."
It seems like you are asking how to ask subjective questions on this site. You might want to read this blog post from the Stack Exchange blog on "Good Subjective, Bad Subjective." The post refers to the following six guidelines for drafting subjective questions:
- Great subjective questions inspire answers that explain “why” and “how”.
- Great subjective questions tend to have long, not short, answers.
- Great subjective questions have a constructive, fair, and impartial tone.
- Great subjective questions invite sharing experiences over opinions.
- Great subjective questions insist that opinion be backed up with facts and references.
- Great subjective questions are more than just mindless social fun.
If you are asking questions about what was more important between a set of things that isn't a good fit for the site. This site tries to focus on questions that can be answered objectively by referencing historical facts. Sometimes you may notice that questions ask "what were the factors that contributed to this event," that may seem like a subjective question, because it is in part. However, that question differs from asking what is important, because it invites the person who answers to answer with factors, but not to make judgment calls amongst those factors.
Hope all this makes sense.