The current version of the chart is a US-centric version, so it has mostly US based sources. To the extent there are some international sources, (i.e., BBC, Al Jazeera, The Economist, etc.), we rate those based on their US-facing coverage, rather than the entirety of their coverage.
We do plan to expand to international versions in the future. By necessity, any version of the chart has to be bound by some geography, such as by country or region, because left-right politics differ around the world. What’s left and right in the US is different from what is left-right in France or Saudi Arabia. Therefore, we don’t have Canadian or many European sources on the US-centric chart.
When we do come out with international versions of the chart, they will be made using analysts with political knowledge and include sources from the particular region for which the version of the chart is made.