Certainly, I think the operating environment of the past few years--which included counterinsurgency against the Palestinians-- contributed to a decline in the IDF's capability. In this sense, too much of an emphasis on counterinsurgency degraded their ability to deal with well-trained teams of Hezbollah fighters. However, to use this to justify proposals to have the US military shift away from counterinsurgency seems alarmist, as it misconstrues the differences between the Palestinians and the Taliban.
Palestine is a far cry from the counterinsurgency campaign in Afghanistan, with even a retired Israeli general noting that, compared to the Palestinians, the Taliban were "tough fighters...real hooligans". Unlike Palestine, battles at Wanat, COP Keating, Tora Bora and Operation Anaconda have been fierce pitched battles between determined light infantry forces not too dissimilar to the fighting Israel faced against Hezbollah. In numerous engagements, ISAF troops have squared off against hundreds of well-trained and well-armed Taliban insurgents in firefights which sometimes last for hours.
While counterinsurgency must, of course, involve population security, economic development, and the promotion of legitimate governments, few counterinsurgency advocates will deny that "kinetic" operations play a critical role. As General David Petraeus, referencing a famous line in the Counterinsurgency Manual, quipped: "Sometimes the best weapons do shoot". Certainly, just by emphasizing counterinsurgency doesn't mean that we let our ability to shoot, maneuver, and communicate atrophy. Yet, apparently, the IDF did.
The culprit, in many cases, appeared to be gross complacency and a lack of discipline. On 11 July 2006, a patrol of IDF Reservists--on their last day of their annual training--set out in two Humvees along the Lebanese border near the town of Zarit. These soldiers were so interested in simply going home to their families that they were grossly careless, conducting little, if any pre-mission planning, and ignored most of their routine operating procedures. They made for easy prey for the Hezbollah team, who had planned their ambush over a period of months.
The US military, though engaged in counterinsurgency, should not forget the basics of pre-combat inspections. A failure to perform the basic, fundamental soldiering tasks will lead to defeat, no matter what type of battlefield you're on.