On Saturday, Britain's prime minister said Russia’s intelligence agencies spied on former double agent Sergei Skripal and his daughter Yulia for at least five years before they were attacked with a nerve agent in March. In a letter to the NATO Secretary General, email accounts of Yulia had been targeted in 2013 by cyber specialists from Russia’s GRU military intelligence service. The Skripals were targeted by what London says was a nerve agent attack that left both of them critically ill for weeks.