A Russian aircraft last month bombed a base in southeast Syria secretly used by American and British forces in order to pressure the Obama administration to better cooperate in the stricken country, U.S. Defense officials told The Wall Street Journal. Just 24 hours before the previously undisclosed June 16 attack, some 20 British special-forces personnel had left the base. Reports do not indicate that anyone was injured. According to the Journal, this event and another Russian strike, on a separate CIA-linked site, were moves by Moscow to pressure the White House to cooperate with its forces. Russian officials did not comment on the allegations. Secretary of State John Kerry reached an agreement last week with the Russian government to work together against the al-Nusra Front. Officials from both the Pentagon and the CIA objected to the provisional agreement.