After months of international controversy over possibly defective Takata Corp. air bags, one thing lawmakers, regulators, the media, carmakers and the parts supplier probably agree on is this: It won't be easy to resolve the crisis. While Takata Chief Executive Officer Shigehisa Takada has avoided public appearances since June, a person close to the company's thinking said it will continue to "thoroughly" conduct tests to determine the cause of the trouble with its inflators, which in some cases can deploy with too much force and spray shrapnel at those onboard.