Russia
An alleged nerve agent attack on Kremlin critic Alexei Navalny in August was the latest political controversy to hit the nearly-completed Nord Stream 2 gas pipeline, as Germany debates whether to halt the project as part of potential sanctions against Russia.
Led by Russia's Gazprom with Western partners, the pipeline, which would double the capacity of the existing Nord Stream 1 link, is more than 90% completed and scheduled to operate from early 2021.
The project has split the European Union, with some members saying it will undermine traditional gas transit state Ukraine and increase energy reliance on Russia.
The United States, keen to increase liquefied natural gas (LNG) sales to Europe, also opposes the pipeline and has targeted some companies involved with sanctions.