WASHINGTON — We are now witnessing a determined counterattack by the Obama administration and its political allies on the matter of health care costs. Many critics (including me) have argued that President Obama’s “reform” agenda wouldn’t control rapidly rising health spending and might speed it up. The logic is simple. People with insurance use more health services than those without. If government insures 30 million or more Americans, health spending will rise. Greater demand will press on limited supply; prices will increase. The best policy: Control spending first; then expand coverage.