The average number of IED (Improvised Explosive Device mostly. car bombs and roadside bombs) attacks in Iraq are down, and the percentage of attacks that are intercepted has been rising. But the casualty rate from IEDs has been rising as well. The primary reason for this is that the terrorists are using increasingly larger bombs. In addition, some attacks have been coordinated so that automatic weapons or RPG fire is used to draw attention away from the actual bomb, thus making it more likely that the distracted drivers will take their vehicles close enough to the bomb to get hurt. This indicates that the terrorists are using more experienced people to set up and use IEDs. The bombs are increasingly detonated by wire, because of the increasing use of jammers by American forces. UAV surveillance is also spotting more IEDs, and even the people setting them up. All of this has forced the terrorists to concentrate on fewer, but much more skillfully set up, IED attacks.
An additional problem is that U.S. forces are increasingly taking the fight into enemy territory (western Iraq), where most of the terrorists have their bases and hide outs. This means its easier for the terrorists to set up more, and larger, IEDs. The overall American casualty rate has been going down, but thats because the terrorists have pretty much given up trying to have gun fights with U.S. troops, and are having a harder time firing mortar shells or rockets at American bases.
The pressure on Syria to stop being a transit area for foreign terrorists entering Iraq has had some effect. Syria claims that it has 5,000 troops on the Iraq border, which carry out 50 patrols each day, in addition to maintaining 557 fixed posts. The Syrians insist this is sufficient to severely limit illegal crossings in the day time. Night time security is dependent on night-vision equipment the U.S. and Britain said they would supply, but so far have not. There are also complaints that the Iraqis have not made a similar effort on their side of the border. This is not true, but the Iraqis have only recently put border police back on the border (they largely disappeared two years ago.)
The Syrians also claim that, recently, they have stopped 1,240 foreign Islamic militants, and some 4,000 Syrian Islamic militants, from crossing into Iraq. Still, Iraqi officials have been blunt in accusing Syria of providing sanctuary for Saddams henchmen, who are still allowed to operate freely in Syria. This includes building car bombs in Syria and driving them across the border illegally, along with suicide bombers, as well as weapons and money for terrorists operations in Iraq. The Syrians are caught in a bind. While they want to please they Iranian allies, they are getting mixed signals from Iran. The Islamic radicals in Iran, who control parts of the military, police and intelligence forces, encourage Syria to assist the Iraqi terrorists, even though these guys are anti-Iran (Saddams followers and al Qaeda). But the Iranian radicals hate the United States so much (as the Great Satan), that they will deal with the devil in order to hurt American efforts to bring real democracy to Iraq. The Iranian radicals tolerate democracy only if religious officials have veto power, like they do in Iran.
Meanwhile, the Iranian government is trying to support the Iraqis, because they understand that an Iraqi democracy will be controlled by Shia Arabs, and their Kurdish allies. This is good for Iran, even if the Iraqi government is not dominated by the Shia clergy if Iraq. Moreover, the Iranians, who are supporting religious groups in Iraq, believe they have a chance of getting a new constitution adopted that gives the religious authorities a lot of power. The Iranian leadership knows that most Iraqis, even Iraqi Shias, dont want a clerical dominated government as exists in Iran. But as the Iraqi committee hustles to write a draft constitution by August 15th, there is still a chance that the religious leaders will get a lot of power. But in the long run, Iran has more influence in Iraq than it has had for centuries. While the Iraqis are mostly Arabs, and the Iranians mainly Indo-European, and have traditionally been enemies for thousands of years, they are united by their Shia religion, which has long been persecuted by the Islamic Sunni majority. Al Qaeda, and the Sunni Arab minority in Iraq, are particularly deadly foes of Shia Islam. Thus, in the grand scheme of things, Iraq and Iran both want these two groups defeated. Its a small, but influential, bunch of radicals in Iran who are obsessed with destroying the United States, and the West in general, that offer some help to al Qaeda. The Iranian Islamic radicals are now accussed of designing and building some of the more sophisticated IEDs used in Iraq. Fanatic flakes like this are what make the Middle East such a dangerous place. These guys are not only way out there in terms of philosophy and goals, but are willing to use murder and suicide in hopeless attempts to achieve their goals. You have to deal with them, if only to kill them. Killing the ones inside Iran could be complicated.