Secretary of Defense James Mattis in front of the Pentagon, Aug. 7, 2018. (Getty Images/Mark Wilson)

(CNSNews.com) - The Lead Inspector General for Operation Inherent Resolve, the U.S. military campaign against the Islamic State in Syria and Iraq, said in his latest report, released Nov. 5, that the Islamic State had lost all of the territory it had once held in Iraq and 99 percent of the territory it once held in Syria.

“With regard to OIR, ISIS has lost control of all of the territory it once controlled in Iraq and remains in control only of an estimated one percent of territory it once held in Syria,” said the report.

The IG report, however, did not claim that the OIR military operation had killed all members of the Islamic State in the region or eliminate sympathy for its cause.

“Overall, the report said that in its assessment a ‘reduced, covert version’ of ISIS will survive in Iraq and Syria and will maintain a presence in neighboring countries and affiliates in multiple countries, including Afghanistan, Libya, Somalia, and Yemen,” said the report.

The report also said the vision of the Islamic State continues to be the creation of a “caliphate.”

“Furthermore, the DoD stated to the media that ISIS is ‘well-positioned to rebuild and work on enabling its physical caliphate to re-emerge,’” said the report. “The DoD also reported that ISIS retains the long-term objective of creating a territorial caliphate.”

Here are some key excerpts from the report:

"With regard to OIR, ISIS has lost control of all of the territory it once controlled in Iraq and remains in control only of an estimated one percent of territory it once held in Syria. This quarter, however, the Department of Defense (DoD) and a United Nations monitoring committee report stated that ISIS continued to move underground and solidify as an insurgency in Iraq and Syria. Despite the loss of almost all of its territory, the terrorist organization kept some of its bureaucratic structures in place and continued to raise funds. These operations, in combination with concerns about both the ability of the Iraqi Security Forces to operate without Coalition support and the ongoing Syrian civil war, raised the potential for an ISIS resurgence. During this quarter, the DoD reiterated that its mission remained the “enduring defeat” of ISIS. However, U.S. policymakers issued statements about Iran and Syria that raised questions about how long U.S. troops will remain in Syria….. "According to the Department of Defense (DoD), ISIS has lost control of all the territory it once controlled in Iraq, and remains in control only of an estimated 1 percent of territory it once held in Syria.1However, both the DoD and a United Nations (UN) Security Council monitoring committee report stated that an effective clandestine ISIS organization appears to be taking hold in both countries.2…. "The DoD reported that ISIS has lost roughly 99 percent of the territory in Syria that it once held.235 Despite this loss, the DoD described ISIS as an “adaptive organization capable of exploiting vulnerabilities in the security environment.”236 Furthermore, the DoD stated to the media that ISIS is “well-positioned to rebuild and work on enabling its physical caliphate to re-emerge.”237 The DoD also reported that ISIS retains the long-term objective of creating a territorial caliphate.238 "The DoD reported that the absence of security in rural and under-governed areas of Syria continued to provide safe haven to ISIS fighters. From these areas, ISIS is deploying guerilla units to exacerbate sectarian tensions and regain Sunni support through a combination of “coercion and cooptation.”239 The DoD stated that the “illegitimacy of the Syrian regime, sectarian divisions within Syrian society, and the enormous task of rebuilding a country ravaged by civil war” left Syria vulnerable to ISIS’s resurgence.240

"The previously referenced report to the UN Security Council also described ISIS as a resurgent group steadily moving underground. The report said that despite damage done to ISIS’s bureaucratic structures, the “collective discipline” of ISIS members remained intact and Abu Bakr al Baghdadi remained its leader.241 The general security, finance, and immigration and logistics “bureaus” remain intact.242 ISIS’s newsletter continues to publish in eastern Syria, which the report considered an “indicator of the financial and organizational health” of the terrorist group.243 On the financial front, ISIS remained able to generate revenue from limited oil smuggling operations, extortion and taxes, kidnapping and other criminal activity, drug trafficking, and external donations. It also continued to draw on cash reserves.244 Overall, the report said that in its assessment a “reduced, covert version” of ISIS will survive in Iraq and Syria and will maintain a presence in neighboring countries and affiliates in multiple countries, including Afghanistan, Libya, Somalia, and Yemen.245 "The DoD did not provide the DoD OIG with an unclassified updated estimate of ISIS strength in Syria this quarter.246 Last quarter, however, the DoD reported to the DoD OIG that between 13,100 and 14,500 ISIS members remained in Syria. That number included 4,000 to 6,000 estimated to be in the U.S. military’s areas of operation.247 The monitoring committee report to the UN Security Council cited similar estimates of ISIS fighters in Syria.248 The DoD said its estimates include former ISIS fighters who remained sympathetic but were no longer fighting, either for “self-preservation or for strategic reasons,” according to a report by the Congressional Research Service.249 More information on ISIS in Syria can be found in the classified appendix. Foreign Terrorist Fighters Remain a Concern "DoD and the United Nations expressed concern about the presence of foreign ISIS fighters in Syria. The monitoring committee report submitted to the UN Security Council said that the net flow of foreign fighters away from Iraq and Syria remained lower than observers had expected. Many fighters, it said, have melted into the local population, while others remain in hiding in neighboring countries. The report said that one UN member state had expressed concern that these fighters planned to “bed down” until the opportunity to return to “active resistance, insurgency, and terrorism.” The report said that no country “has emerged as a favorite destination,” but that many fighters had made their way to Afghanistan.250 "In Syria, the SDF continued to detain at least 600 foreign ISIS fighters from more than 40 countries in detention centers in the northeast, according to the DoD.251 U.S. officials continued to urge countries to repatriate fighters, and were calling on all countries to provide a long-term solution to ensure that detained foreign terrorist fighters did not become a threat again.252 In August, General Votel praised Macedonia for marking a “significant milestone” in the effort to repatriate foreign ISIS fighters.253