By Parisa Hafezi and Humeyra Pamuk DUBAI/WASHINGTON (Reuters) – Russia said on Tuesday it has received written guarantees it can carry out its work as a party to the Iran nuclear deal, suggesting that Moscow would allow a revival of the tattered 2015 pact to go forward. Russian Foreign Minister Sergei Lavrov’s comments appeared to signal Moscow may have backed off its previous view that Western sanctions imposed on Russia over its invasion of Ukraine were an impediment to salvaging the nuclear deal. Lavrov on March 5 unexpectedly demanded sweeping guarantees that Russian trade with Iran would …