"Defense officials and reports indicate that the maximum pressure campaign has not weakened Iran strategically or caused a reduction in Iran's regional influence," Kenneth Katzman, a specialist at the Congressional Research Service, wrote in an article for the Atlantic Council, an American think tank, in a private capacity.
He said the effectiveness of any US policy needs to be measured against the primary objective it is seeking to accomplish, according to Financial Tribune.
"A policy might be changing some conditions in a target country, but not others. The conditions that are being changed by US policy might be material to US interests, or they might not. The key question is whether the policy is affecting the core variables the United States seeks to affect, and in the ways sought by the United States."
According to Katzman, US sanctions imposed after US President Donald Trump's withdrawal from the multilateral nuclear accord with Iran—known as the Joint Comprehensive Plan of Action—have negatively affected its economy.
"In October 2019, the International Monetary Fund revised downward its estimates for Iran's GDP for the March 2019-March 2020 period to a shrinkage of about 9.5%," the article read.
However, he believes that Trump's strategy has not produced the intended results when it comes to demands pertaining to Iran's regional activities as stipulated in a May 21, 2018, speech by US Secretary of State Mike Pompeo at the Heritage Foundation.
He was referring to the time when the US chief diplomat set out 12 tough demands for inclusion in a new nuclear treaty with Iran, including ending support for ideologically aligned regional groups, to alter Iran’s regional policies.
Iran's Military Prowess
Katzman said the US has failed to force a change in the strategies pursued by Tehran in the region.
On Nov. 23, in advance of the "Manama Dialogue" security conference in Bahrain, US Central Command Commander General Kenneth McKenzie publicly assessed that the US buildup would deter Iranian attacks on US targets but referred to its limitations as well, the article read.
"Gen. McKenzie's comments reinforced the conclusions of the 2019 version of the Defense Intelligence Agency's report on the military power of Iran, released in mid-November," Katzman said.
The expert further said that to try to deter Iran, the US has deployed 14,000 additional US forces to various facilities in the Persian Gulf states, adding to the 60,000 US forces that were already in theater, as well as sending additional missile defense batteries and US combat aircraft.
"The United States also established a multilateral maritime security operation, the International Maritime Security Construct," he added.
Katzman says there have been no indications that Iran is willing to accept, in any negotiation, the core goals of the US maximum pressure strategy—the retrenchment of Iran's regional power projection capabilities and support for any of its regional allies.