Poland held a memorial yesterday to mark the plane crash last year that killed President Lech Kaczynski (RFE/RL has details and speech soundbites, and the BBC has some video footage), as the former President’s twin brother shunned the event, blaming Moscow and Prime Minister Donald Tusk for the crash. ‘A recent poll shows that a majority of Poles feel there has still not been an adequate explanation of what happened.‘  President Bronislaw Komorowski is in Russia today for a further commemoration event.  A new row has emerged after Moscow apparently changed a plaque marking the event in Smolensk to remove a reference to the Katyn massacre (‘Moscow’s efforts to cover up responsibility for the massacre have long been a major irritant in relations between Poland and Russia‘).  Day of Wrath protests in Moscow saw 250 protesters gathering (click for video), with ‘about a dozen‘ of them detained.  Deputy Prime Minister Sergei Ivanov says that Russia will join the U.S.’ planned missile shield in exchange for a joint, ‘red-button push to start‘ role in operating it.