It was the first serious terrorist attack in the nation since 9/11.
The FBA and the CIB were in a complete meltdown. No one knew how those fully armored fighters appeared, how they crossed the borders, nor how they cleared custom. Not to mention, how they transported the heavy firepowers to Los Santos.
Fifteen minutes passed since those terrorists entered the embassy and SWAT reinforcement finally arrived to surround the embassy with armored vehicles. The Los Santos Police Department never faced such an embarrassing defeat. The founder of the modern SWAT team, the LSPD SWAT team, was terrorized by the firepower of the terrorists.
After the terrorists secured the embassy, they mounted light machine guns at the windows and used the hostages at hand to threaten the special forces from approaching. These people neither submitted their requests nor expressed their intention to negotiate.
For a while the situation was in a stalemate.