Complex sentence: U.S. President Barack Obama strongly condemned this outrageous attack "on U.S. diplomatic facilities while also stating that" (s) ince our founding, the United States has been a nation that respects all faiths.
Split into simpler sentences: U.S. President Barack Obama said that he strongly condemned this outrageous attack "on U.S. diplomatic facilities." Since our founding, the United States has been a nation that respects all faiths.