I think that there are several points that can help to form a thesis statement from Yeats' poem. Yet, without more specificity, you will have to piece things together. I think that one potential area where a thesis statement can be developed is how the work was able to foretell the rise of Hitler. In a political setting where "things fall apart" and where "the center cannot hold," Yeats explores how such a condition can result in the rise of a centralized authority figure that can end up being far worse than the desolation of the condition where there is no leadership. Yeats' poem details the landscape of Europe, making it ripe for the rise of fascist rulers in the 1930s. Another area where a thesis can be developed would be on how the poem can serve as an example of both Modernism and Post- Modernism. The poem is a great sample of the challenges the Modernists saw in the context of the early 20th Century. At the same time, I think that a case can be made for how the poem speaks to a Postmodern world where the only absolute is the sense of freedom. I think that this might be another particular area where a thesis statement area. Yet, I think that without specificity and narrowing down in terms of what exactly the topic area upon which the thesis statement has to be focused, it will be a challenge to suggest a possible thesis statement.