So far this year, the U.S. has had 291 troops killed in Afghanistan, and 115 in Iraq. The war has definitely shifted from Iraq to Afghanistan. But it's a very different kind of war in Afghanistan. For one thing, the population is more rural than in Iraq. The country folk are more tribal than those in Iraq, and more warlike.
But the big difference is the lack of drug gangs. Afghanistan is the source of most of the world's heroin production. While Iraq has lots of oil, that's legal money. The heroin brings the few dozen gangs that produce and process the stuff several billion dollars a year. That's a quarter of the GDP, most of it profit (even after bribing thousands of officials and officers). A few percent of that money goes to the Taliban, who do most of the fighting to protect the heroin business. While there is some al Qaeda terrorism in Afghanistan, it's much less than in Iraq (at the peak in 2007, or even today.)
Afghanistan also has more private armies (warlords, some of them also provincial governors, others are Taliban leaders or drug lords). Lots of those heroin profits have gone into buying weapons, vehicles and satellite phones. While some of the billions Saddam looted from Iraq, went into the terrorist campaign after 2003, there's a lot more cash in play in Afghanistan. It's only recently that foreign politicians and military commanders have described the fighting as a war against drug gangs, but that's what it's been for a long time.
Another angle that has gone largely unreported is the extent to which Afghan media has been bought, or terrorized into submission. Same thing with government and tribal officials. This has resulted in a very successful media campaign in support of the Taliban use of civilians as human shields. Even though far fewer civilians are killed in Afghanistan (1,013 so far this year, compared to 2,107 in Iraq), the heroin money has led to new ROE (Rules of Engagement) that basically make Taliban or drug gang gunmen immune from attack if they are in the company of civilians. Now that is clout.