Analysis - Emboldened in Syria and Iraq, Islamic State may be reaching limits of expansion

Militant Islamist fighters take part in a military parade along the streets of northern Raqqa province June 30, 2014. REUTERS/Stringer

LONDON (Reuters) - With its two biggest victories in nearly a year in Iraq and Syria, Islamic State has energized its fighters, littered the streets of two cities with the bodies of its enemies and forced Washington to re-examine its strategy.

The near simultaneous capture this month of Ramadi west of Baghdad and Palmyra northeast of Damascus has reinforced the sway of the self-proclaimed caliphate of all Muslims closer to the ramparts of Islam's two great historic capitals.