From the Calvinist blog Triablogue:
iii) Take Arminians who affirm divine foreknowledge. How did the Arminian God not plan or will the foreseeable consequences of his own actions? If he knew in advance that by making the world, humans would fall into sin, how did he not will that outcome? Likewise, if he saw it coming, as a result of his creative fiat, how could that still be an unplanned consequence of his actions? Keep in mind, too, that according to Arminian concurrence, God enables the sinner to sin.