Halliburton, currently the largest military contractor in Iraq, said it will move its corporate headquarters from Houston to Dubai. The shift is part of a strategic plan to focus on expanding relations with state-owned oil companies, the company said. The Dubai announcement, which comes at a time when Halliburton is under investigation by government agencies over allegations of improper business dealings, has drawn criticism from politicians including Senator Hillary Clinton. Critics are questioning whether the move is really an effort to avoid taxes and recent legal inquiries.