In the two years following the July 2015 signing of the Iran nuclear agreement, there had been reports of approximately 50 such incidents, in which the IRGC boats maneuvered close to American ships, often at high rates of speed and with their weapons on display. In some cases, the crews of the Iranian vessels refused to deviate from their course until the US Navy had fired warning shots after first signaling with radio broadcasts, lights, and sirens.

But the last of these incidents took place in July, and there have evidently been no significant encounters of this nature in the intervening six months. According to Newser, the US military has no official explanation for why the IRGC’s behavior has changed, but the report quotes Ali Vaezi of the International Crisis Group as speculating that Tehran is exhibiting more caution out of fear that aggressive gestures will give the Trump administration justification for reprisals.

US President Donald Trump spearheaded an increase in the assertiveness of US policy toward Iran almost immediately after he took office. The change includes the imposition of new sanctions related to Iran’s regional aggression and non-nuclear activities. Trump has also continued to threaten the nuclear deal, or Joint Comprehensive Plan of Action, which he described on the campaign trail as the “worst deal ever”.

Trump’s refusal to certify Iranian compliance with the JCPOA in October was largely based on the notion that Tehran had violated the “spirit” of the agreement through ballistic missile tests and other activities deemed to be out of keeping with the deal’s preamble, which expressed expectations that its signing would lead to improvements in global peace and security. Resulting concerns over the possible re-imposition of nuclear-related sanctions have effectively discouraged Western businesses from investing in the Islamic Republic, thereby slowing the economic recovery that Tehran expected to follow the nuclear negotiations.

Naturally, the furtherance of this trend is something that Iran would like to avoid, to say nothing of the additional threat of a possible open confrontation between a persistently aggressive IRGC and the US military under the reactionary leadership of the Trump administration. In the wake of the October decertification, the White House also revealed a national security strategy that included greater freedom for military officials in responding to perceived threats from entities like the Iranian regime.

The Trump administration’s foreign policy also entails improved ties with longstanding allies in the Middle East, most of which are bitter adversaries of the Islamic Republic. Iran and Saudi Arabia have been engaged in a significant war of words for many months, set against the backdrop of a proxy war in Yemen and a more general competition for influence over the region as a whole. EA Worldview indicated on Friday that this Arab-Iranian conflict had been on display at the World Economic Forum in Davos, Switzerland this week, which was also attended by President Trump.

In a speech before that gathering, Saudi Minister of Foreign Affairs Adel al-Jubeir accused Iran of using “sectarianism and terrorism” as part of its effort to establish regional hegemony and “restore an empire that was destroyed thousands of years ago.” Jubeir’s Iranian counterpart Javad Zarif had been scheduled to be in attendance at Davos but cancelled at the last minute. Nonetheless, he responded to Jubeir via Twitter, where he insisted that both the Kingdom of Saudi Arabia and the United States had armed the Islamic State of Iraq and the Levant, which Tehran takes credit for destroying through its interventions into nearby conflicts.

Saudi Arabia and the US share concerns over the destabilizing effects of increased Iranian influence in those conflict zones. These concerns have also been eagerly voiced by Israel, most recently through a speech to the United Nations by Israeli Ambassador Danny Danon. The Associated Press reported upon that meeting on Friday and quoted Danon as saying that Iran was striving to turn Syria into the “largest military base in the world” in the wake of that country’s devastating seven-year civil war.

Danon reported that approximately 82,000 fighters in Syria remained under Iranian command. This number consists of some local fighters, along with members of the IRGC’s foreign expeditionary wing known as the Quds Force, plus Shiite militants recruited from other areas including Afghanistan and Pakistan. Danon also noted that the Islamic Republic had spent hundreds of millions of dollars on deepening its foothold, particularly through the development of an overland route connecting Tehran to Damascus by passing through Iraq.

The development of this supply route is widely regarded as a prominent threat to Western interests in the region, and it appears to be a particular strategic focus for the Trump administration. This may indicate increased sensitivity on the part of the White House to perceived Iranian threats, and awareness of this situation may have prompted Tehran to be more cautious about its behavior at sea while pursuing continued expansionism on land.

This same situation adds context to recent communications between the US and other Iranian adversaries. As an example of this, House Speaker Paul Ryan undertook an Arab tour this week during which confrontation of Iranian influence was reportedly a major topic of focus. The National Council of Resistance of Iran emphasized this aspect of Ryan’s meeting with King Salman of Saudi Arabia. Meanwhile, the Associated Press reported that Ryan had provided specific assurances to the government of the United Arab Emirates about America’s commitment to a hard stance on Iran’s ballistic missile development and the proliferation of Iranian proxies in the broader Middle East.

Ryan’s comments apparently give legislative backing to a strategy that had primarily been credited only to the White House. In fact, the House Speaker even specifically indicated that Congress was prepared to take appropriate measures including the imposition of new sanctions to forestall these threatening Iranian behaviors. To the extent that this represents a sign of unity within the US government, it may also be leveraged to secure greater consensus among America’s European partners – a goal the Trump administration has been vigorously pursuing.

On his trip to the Gulf, Ryan contributed to the dialogue on this subject as well. The Middle East and North Africa Financial Network quoted him as saying that the US and Europe had begun serious discussions over the possibility of internationally-enforced sanctions over the same issues highlighted by the White House and by Ryan himself. Some such discussions are scheduled to take place on Monday when representatives of the United Nations Security Council travel to Washington in order to directly examine the recovered weapons components that were put on display last month at a press conference led by US Ambassador to the UN Nikki Haley.

Agence France Presse reported upon the development on Friday and recalled attention to what Haley had said about weapons that included a ballistic missile fired at Saudi Arabia by Houthi rebels in Yemen: “The evidence is undeniable. The weapons might as well have had ‘Made in Iran’ stickers all over it.”

The report noted that the UN had so far been somewhat more equivocal on this topic but acknowledged that there were signs of Iranian manufacture and that the Islamic Republic had at least failed to prevent its weapons from being handed over to foreign entities. The White House presumably anticipates that the Security Council will be more thoroughly convinced in the coming week, and Haley reportedly hopes to persuade the body to agree on the need for sanctions or other coordinated measures against Iran’s violation of arms embargos and restrictions on its ballistic missile development.

This, of course, will be a difficult thing to achieve in light of the close relationships that Iran enjoys with two of the Security Council’s five permanent members, Russia and China. But the continued accumulation of evidence for Iranian misbehavior will no doubt help the White House in its effort to overcome resistance from those Iranian allies. This may be a reason for Tehran to be wary of making threatening gestures that do not meaningfully contribute to the regime’s foreign policy goals.

Empty threats against US Navy ships might fall into this category, as might provocative ballistic missile tests. Both of these activities appear to have slowed since President Trump took office. Fox News reported on Wednesday that while Iran had tested 10 or 11 nuclear-capable ballistic missiles in 2016, the figure for 2016 was only four or five. These figures were extracted from a report by the Foundation for Defense of Democracies, which also reported that launches of other types of ballistic missiles brought the total number for the two years up to 23.

While the Iranian regime has reportedly diminished the frequency of some of its provocative gestures, this is not indicative of a general shift toward a more moderate foreign policy. Quite the contrary, there are clear signs of increases in activities that have more substantive effects upon Iran’s position in the Middle East. For instance, the National Council of Resistance of Iran reported on Thursday that the budget for Iranian military projects had increased by 128 percent over the past four years.

As evidence that this trend remains ongoing, the NCRI points to the news that four billion dollars had been withdrawn from the country’s National Development Fund as part of the coming year’s budget, 2.5 billion dollars of which is earmarked for military activities. Total military expenditures under the new budget are 10 billion dollars, and undisclosed spending on the IRGC and the Intelligence Ministry likely push the real figure even higher.