By Kanishka Singh WASHINGTON (Reuters) – A New Jersey man arrested in Kenya has been charged for trying to aid militant Islamist group al Shabaab, the U.S. Justice Department said, alleging he was motivated by Hamas’ Oct. 7 attack on Israel to wage violence. The arrest comes amid heightened incidents of antisemitism and Islamophobia in the wake of the Israel-Gaza war, which have raised terror threat levels in the United States. Karrem Nasr, a U.S. citizen who moved from New Jersey to Egypt around July, was taken into custody in Nairobi on Dec. 14 and brought to the United States on Thursday, t…