You've put your finger on one of the tensions in the underlying logic of undergraduate level history work, perhaps particularly in the UK. We want you to get into the habit of writing substantively - that is, writing with the aim of convincing the reader through evidence and analysis. This means that we don't want you to rely on other scholars' views uncritically, we want you to think about what we know about the subject and how we know it, what the different possible interpretations are, and come to your own, independent conclusions about the best answer to the question at hand. But, at the same time, the constraints of your degree mean that most of your evidence is still going to be coming from other historians' work, since it's not like you can pop down to the National Archives at Kew each time you've got an essay due. Your actual independence is therefore a bit illusory.

Your dissertation, in theory, should be the time where you escape this logical bind, and do the groundwork for yourself. Your dissertation topic is often actually narrower than an essay topic, despite being longer - the idea is that you're picking a smaller, more constrained topic for which you can locate a cohesive, manageable source base. This means that for a good dissertation, the bulk of what you write is being built on the foundation of relevant primary source material, and your claims/argument is being substantiated by reference to these sources.

This doesn't mean that secondary sources are irrelevant to your project. While no one may have written about your exact topic, people will have written things that are relevant to you. Maybe you're doing a case study of a particular event, place or person which has relevance to wider debates. Maybe other historians have used the same methods or approach you want to use, and you can use them as a model for your analysis. Maybe historians have mentioned your topic in passing, but you're going into more depth. Your goal is to show that you're aware of how your argument and analysis is fitting into and contributing to this wider field - why would historians who have written about these wider contexts care about what you have to say, in other words. This is historiography, the fine art of understanding the wider scholarly context to the specific history you are writing. You mentioned you're doing a topic related to the Cold War - say you want to focus on the British response to the Cuban Missle Crisis. You might look at the records of Cabinet Meetings in these crucial weeks, analysing how the British government responded to and understood the crisis, substantiating your views through reference to these records. Your historiographical goal, however, would be to show how your specific analysis might be relevant to wider histories of the Crisis, or British political histories of the Cold War, or the history of cabinet government.

This means that there is a lot of synergy between primary source analysis and historiography - doing both well is key to a successful dissertation. As your supervisor said, your own analysis and arguments need to be substantiated directly through your primary research, but you should still be seeking to contextualise and relate this analysis to other historians' work to draw out wider significance and meaning to your work.

Every academic history paper *should* be considered an opinion supported by facts, in a nutshell. The most concrete way to find out fact vs an author's opinion from your stated position, however, is to check the author's sources, and see how much of what they wrote is from the source, and what was added by themselves. So, for your example, a country was willing to negotiate? What's the historian's evidence that they were? Look into the footnotes for that section. Once you check that, you should have a clearer understanding of where the author and evidence meet. Did the head of state say in a press conference that the country was willing to negotiate? Hey, then count that as a fact, Jack. That shit holds up in court. But, was the historian's statement based on piecing together more apocryphal, or abstract, statements? Opinion. It takes work and practice, and that's ok. Critical reading is a skill, so it needs to be honed. You're not born with it. Also, change your mindset. Question everything, even presented facts. Don't take anything for granted, every author you read is going to have bias and purpose. Don't trust their benevolence, prove or disprove it.

Hi - we as mods have approved this thread, because while this is a homework question, it is asking for clarification or resources, rather than the answer itself, which is fine according to our rules. This policy is further explained in this Rules Roundtable thread and this META Thread.

As a result, we'd also like to remind potential answerers to follow our rules on homework - please make sure that your answers focus appropriately on clarifications and detailing the resources that OP could be using.

Additionally, while users may be able to help you out with specifics relating to your question, we also have plenty of information on /r/AskHistorians on how to find and understand good sources in general. For instance, please check out our six-part series, "Finding and Understanding Sources", which has a wealth of information that may be useful for finding and understanding information for your essay.