To amplify the previous, while the charger may supply up to 2A, if the phone only draws 700mA that is all it is going to draw.
Also, a lot of 2A chargers are designed for iDevices and their weird way of the charger signaling to the device that it is ok to draw max power. Absent fairly specific voltages on the data lines iDevices will either assume they are connected to a computer and only draw 500mA, or they won't charge at all (I know some newer macs have higher power USB ports but lets ignore that for now). However, most non-iDevices simply look for the two data lines to be shorted together to let them know they are connected to a dedicated high power charger and not a computer. That means that most non-iDevices will not recognize 2A chargers that are designed for Apple products as being high-power and so the phone will only draw 500mA even hooked up to a 2A charger.