However, at the time of its signing, Iran was in a state of great unrest and therefore its terms were "widely disregarded and ignored". The historian Rudi Matthee noted: "The massive unrest in Iran that followed shortly made practical implementation utterly impossible." A few years later, in 1722, when the Safavid state had already entered the final stages of collapse, Russia used the treaty combination with the deaths of Russian merchants in the 1721 sack of Shamakhi as the "casus belli" to invade Iran.