Amid the hullabaloo regarding the handover of Iraqi cities to Iraqi security forces yesterday, it is easy to lose sight of the war still going on. Despite dramatic drops in violence in Iraq since 2006-2007 — and a corresponding increase in violence in Afghanistan — Iraq remains by several statistical measures the more violent of the two.

So far this year 101 U.S. soldiers have been killed in Iraq versus 86 in Afghanistan. Figures for civilian casualties are less exact but they also indicate more deaths in Iraq — 893 in Iraq compared to 680 in Afghanistan.

It is hard to get too worked up over statistics so it helps to put a human face on them — a face like Tim Karcher’s. A lieutenant colonel and battalion commander, Karcher had only recently handed over control of his Area of Operations in Sadr City to the Iraqis. On Sunday he was riding through Baghdad in his heavily-armored MRAP vehicle when he was hit by a devastating EFP (explosively formed penetrator). MRAP’s are some of the best armored vehicles that we have, but EFP’s can punch through anything. As ABC’s Martha Raddatz relates in this moving dispatch, Karcher wound up losing both his legs. Sandstorms made it impossible to medivac him by air, so his command sergeant major, Richard Franklin, drove him to the hospital where doctors managed to save his life. On the way back from the hospital, the sergeant-major’s convoy was hit by another EFP, this one killing a sergeant.

Those EFP’s could have come from only one place — Iran. These tragic and maddening incidents are further confirmation, if any were needed, that Iran has not given up destabilizing Iraq and fighting our troops (and those of Iraq by proxy). The remnants of al Qaeda in Iraq also continue to fight. Their capabilities are thankfully much reduced from what they were several years ago, but they remain a formidable threat.

As long as we have 130,000 troops in Iraq, there is little doubt that we can help the Iraqis maintain the progress that has been made in recent years — although that task becomes a bit harder now that most of our troops have left urban centers. The real test will come in a 18 months’ time when under the terms of the Status of Forces agreement, U.S. troops are due to leave Iraq altogether.

Until recently I had expected that this deadline would not be binding, and there is still a chance that it won’t be, but the zeal with which the Maliki government has insisted on a real (if far from complete) pullout of U.S. troops from Iraqi cities suggests that there will not be many U.S. troops left in Iraq after 2010. That is a worrisome prospect because, for all the gains made by Iraqi security forces, they still have a long way to go before they can police their country entirely by themselves — especially when they face such a potent threat emanating from across the border with Iran.