US President Joe Biden and Western leaders have described “unprecedented” economic penalties and sanctions “with massive consequences” in the event Russia invades Ukraine. Here is a breakdown of what those measures could be and what impact they might have: Washington has teased the possibility of targeting sanctions directly against Russian President Vladimir Putin, a largely symbolic move mimicking those brought against authoritarian strongmen like ex-Libyan leader Moamer Kadhafi and Syrian President Bashar al-Assad. When Biden raised the possibility of targeting Putin this week, he did not specify what shape the sanctions could take, but generally these measures include freezing personal assets abroad and barring foreign bank transactions. The Kremlin said in response the move would be pointless since Russian officials are barred from holding wealth abroad and that it would damage diplomacy on the Ukraine crisis. A potentially more damaging step discussed in Western capitals would be to ban Russian banks’ transactions in dollars — the key currency on international markets — or excluding Moscow from SWIFT, a key mechanism of international banking exchanges. Iran has suffered from having been excluded from the tool and, in the case of Russia, its crucial oil and gas sector would be expected to be badly hit. Another potential sanctions target is the controversial Nord Stream 2 pipeline connecting Russia with Germany. With construction complete, it is set to double natural gas supplies to Europe. Also on the table is the possibility of banning exports of crucial technologies to Russia. Russia has weathered waves of Western sanctions in the wake of its annexation of the Crimean peninsula from Ukraine in 2014, which hit the ruble and saw foreign investment dwindle. In response, Moscow built up what is referred to as “fortress Russia”, measures designed to ensure new sanctions won’t see the economy or Russia’s financial system collapse. As of January 1, the National Wealth Fund, the country’s sovereign wealth fund, had assets worth $182 billion, or nearly 12 percent of gross domestic product, according to the finance ministry.