Will Yemen be the field of American-Iranian war ?
Over the past few weeks, tensions have increased on both blanks of the Gulf water. The United States has deployed battleships and missile launchers to counter a "potential threat from Iran," prompting fears of a devastating war that may affect the Arabian Peninsula and the rest of the region.
As tensions escalated, four tankers - three of them are oil tankers, owned by Saudi Arabia, were attacked off the port of Fujairah on the UAE waters (May 12). Two days later, the Houthis targeted two pipelines deep inside Saudi Arabia. The oil supply through that pipe to Yanbo port on the Red Sea was halted for days. While Saudi accused Iran of being involved in targeting the oil pipelines, no one has been accused of targeting "oil tankers". In June, two oil vessels were attacked in the Sea of Oman, the first was carrying the flag of Panama and the second was carrying the flag of the Marshall Islands. The two were carrying oil shipments from Saudi and UAE to East Asia. The attacks did not lead to casualties. The United States and UK held Iran responsible for the attack. The Gulf States and their allies considered it an unacceptable escalation of tensions by Iran. Iran has denied its responsibility.
Is it war or a new nuclear agreement?
The United States has withdrawn from the Joint Action Plan (the nuclear deal) with Iran and imposed new economic sanctions on Tehran in order to reduce the Iranian oil exports to zero in an American effort to bring Iran back to negotiations on the nuclear deal to take tougher procedures against Iran and its policies in the region. The European Union countries have refused to withdraw from the deal despite the US pressure.
Months after Trump's withdrawal from the nuclear deal (May 2018), Washington imposed sanctions that cut Iran's oil exports from 2.5 million barrels per day to about 400,000 barrels by the end of May - oil revenues accounted for about 40 percent of the total budget of Iran. Meanwhile, Washington also imposed sanctions on Iran's mining sector, which accounts for 10 percent of Iran's total exports, and on Iran's petrochemical sector, which exports about $ 14 billion per a year. The sanctions have had a big impact on Iran's economy, but support to the regime may increase, especially after placing the Iranian Revolutionary Guards on the American lists of terrorism. 
The United States has expected an Iranian response to the sanctions. But Tehran will try to circumvent the sanctions and sell "oil" in the black market, although the interest will be much lower. In order to avoid a reaction and be prepared for deterrence, Washington decided to gradually strengthen its military capabilities and presence in the region. On May 9, 2019, the USS Abraham Lincoln sent its 27-piece combat group including battleships, destroyers and submarines. On the same day, four B-52 launchers, which can carry nuclear weapons, and thousands of soldiers were sent to the region in June, but that is not enough to wage a direct war.
Strategies for playing outside the circle of war:
Iran and the United States have very dangerous strategies that do not lead to war - and they do not want it - but they could push the region into war by accident. 
US strategy: The United States uses the "maximum pressure" policy to force Iran to attend new negotiations on a new agreement that responds to its demands that include the renegotiating on Iran’s nuclear program, its missile program and its regional influence. Some US circles suggest that attacks in the Gulf waters fuel Trump's and his aides' demands to find a cause that justifies a war in the region, just as Bush did before the 2003 invasion of Iraq. But if that was true, it would have been possible to exploit the shooting down of a US unmanned drone on June 20 by Iran as a justification to launch limited military strikes on Iranian positions. But Trump has already stopped this with illogical reasons. Trump said the episode would have been far more serious if the aircraft had been a piloted vehicle, and not a drone. It made “a big, big difference” that an American pilot was not threatened, he told reporters.
Washington needs European and international support against Iran, but withdrawing from the nuclear deal and sending troops to the Middle East ignites international fear and makes it volatile to a war that could destroy the world's energy interests. Although the European Union is trying to circumvent US sanctions, the INSTEX mechanism to facilitate financial and trade movement with Iran is not enough to overcome US sanctions, which will be doubled in the coming period.
At the same time, the results of the US strategy of “maximum pressure” cannot be expected and Tehran depends upon its experience with blockade for the past 40 years to show its ability to withstand.
Iran's strategy: Iran uses the policy of “the Edge of the Abyss” to counter US sanctions by threats and actions in the region through the Revolutionary Guards - classified as a terrorist group in the United States - and its arms in the region.
Although Iran has denied any involvement in targeting oil ships in the Arabian Gulf, it has threatened to stop oil exports from the Persian Gulf in response to blocking its oil exports. Tehran will not be able to close the Strait of Hormuz, which is the passage for 30 percent of the world's oil, so as not to provoke the Europeans, China and Russia and give a justification to the United States to strike it. But targeting oil ships without claiming responsibility by any party creates worries in the energy market. In this context, the Houthis targeted two Saudi oil pumps west of Riyadh which are linked to the Kingdom's oil port on the Red Sea.
Tehran will try to withstand against the US sanctions and to maneuver until the coming US elections in November 2020, hoping that Trump will lose and a new president, whom it can deal with, will come to power. At the same time, a party within Iran may drag the United States into a limited military operation to increase its popularity at home. This party includes the Revolutionary Guard and Al-Morshed “the Guide.”
And because Iran knows very well that a direct war will lead to its loss, it will resort to testing the loyalty of its instruments in the Middle East, especially in Yemen, Iraq and Syria. Therefore, the United States and Iran may move the battle to the region, particularly Yemen.
Reflection of US-Iranian tension on Yemen:
The avoidance of escalation between Iran and the United States will be difficult due to the radical nature of the two regimes and because the parties are not ready yet to make any concession in what is put on the table. The battle may go beyond tension in the Gulf waters to a wider tension in the region where Iran has influence. Yemen seems to be a candidate for this new escalation as Yemen, from the Iranian point of view, is the battlefield that offers better results in highlighting Iran's influence in the region with lower costs than in Iraq and Syria. From the American point of view, Yemen is important to secure its allies in the Gulf region against the Houthi threats that target vital installations in the Gulf region and the corridors of international trade and oil corridors in the Strait of Bab al-Mandab.
This is evident in remarks made by the American envoy for the Iranian file Brian Hawk after a meeting in Jeddah with Saudi Deputy Defense Minister Prince Khalid bin Salman (June 21, 2019) - after the incident of the downing of a US drone. Hook said that if Iran is not countered in Yemen, the risk of a regional conflict in the Middle East will increase. He said: "Iran should not have a foothold in Yemen so as not to threaten Bab al-Mandab." He said that Iran's efforts to use agents to attack Saudi Arabia and destabilize the region must be addressed. 
As tensions between Iran and the United States escalated, the Houthis announced that it will target 300 vital Saudi and Emirati facilities. The Houthis began with targeting two Saudi oil pumps with two suicide drone aircrafts. The Houthis also targeted Saudi airports including Najran and Jazan with a drone aircraft, and the airport of "Abha" with a cruise missile. The smart "cruise" missile is very similar to the Iranian "Sumar" missile, which entered the service line in 2015. The Houthis also dropped down a US drone (MQ-9) in the Red Sea in the same month. Washington said the missile was "Iranian-made." , 
Saudi Arabia described the Houthi attack on Saudi oil pumps as a work done by the Iranian Revolutionary Guard and said the fact that the Houthis are part of the Iranian organization that is on the US terrorist lists.  It means an escalation in the rhetoric of the Arab Coalition due to the new regional tensions. At the same time, Riyadh does not want to increase the number of international and regional actors in Yemen as this may result in losing Saudi full control on the situation and may expose its ongoing operations since four years to a major failure. But as US tensions mount with Iran, the United States may go beyond supporting the Arab coalition to confront the Houthis to bigger and broader deterrence measures.
At the same time, Iran has a big influence on the armed Houthi group, which has grown significantly after the Arab coalition operations, as the group relies much more on the Iranian support that includes weapons, policy and media. At the same time, the Houthis have their own internal goals in the war against the legitimate government, backed by the Saudi-led coalition.
Therefore, it is possible to point to the impact of tension in the Gulf waters on the situation in Yemen:
• What happened in the Gulf waters cannot be separated from the Houthi attacks against vital installations inside Saudi Arabia, or previous Houthi attacks on oil vessels in the Red Sea and attempting to influence shipping in Bab al-Mandab Strait. Therefore, Iran, as it has sent a message that it can stop the oil exports by targeting vessels and referring the attacks against unknown, the Houthis attacks on two oil pumps was an Iranian message that it can disrupt the Saudi oil that that goes to the Red Sea.
• The Houthis will prefer to serve Iran's interests and needs before their own interests. At least for now, the group cannot fail in the Iranian test for the loyalty of the group. It is clear that this will prevail over the group, which may suffer conflicting resolutions between leaders who are the most loyal to Iran and the less loyal and "demagogic" leaders who give priority to the group's interests before Iran's needs. This puts the group in another test and there may be some arrests and assassinations against those who reject to give priority to the interests of Iran.
• The Houthis announced plans to hit 300 targets of vital installations in Saudi Arabia and the UAE, days after they claimed the implementation of the first phase of the withdrawal of their members from the ports of Hodeidah in implementation of the Stockholm agreement. This announcement makes the peace process at a critical risk in contrary to their claim that they have done what pushed the peace process forward.
• If tensions between Iran and the United States increase and if the escalation does not decrease, and if Washington attacks Tehran's tools as part of the US policy of "maximum pressure", Yemen will be a new battlefield that could push the region to a regional war and international polarization. Iran and the EU are currently engaged in consultations on Yemen, the last of which was held in June 2019. 
• If tensions range extends and Saudi Arabia fears an increase in international actors in Yemen, it may resort to agreements with the Houthis, which would not be in the interest of the legitimate government, which is already suffering from a diminished influence in the liberated areas as a result of the growing of the Suadi-UAE influence.
Weapon of loyalty:
The Houthi group is more loyal to Iran and it cannot abandon Iran - at least for now. Tehran will press to stop any progress in the Yemeni peace process until the Houthi missiles and drones press Saudi Arabia and the United Arab Emirates. This of course would complicate the UN efforts, if international actors in Yemen expand. Every time tension increases, the legitimate government and the coalition will have to rush to make a major military victory against the Houthis to limit the arsenal they are building. Thus, the Houthis will not sit on the table of negotiations to restore the state institutions in Yemen. The group will become a key actor in the US-Iranian game of strategies in the region.
Iran believes that its influence in the Middle East by using non-official actors contributes to its national security and protects the Iranian regime from decades-long Gulf threat. It is therefore difficult for Iran to abandon its allies in the region. On the contrary, away from the rhetoric of Saudi escalation, Saudi believes that the Houthi group is not fully loyal to Iran and that the group can abandon Tehran if it got an agreement that keeps it in power or, as the recent US initiative says, gives the Houthis a region to rule as a "minority" . It is hard for the Houthis to abandon Iran even if they declare that to Riyadh. The group has become more connected to Iran and the Lebanese Hezbollah so that it is difficult to abandon them.
Therefore, the situation in Yemen is no longer as it was. In addition to complexities of its internal problems, another complexity related to the regional and international conflict with Iran is added to the Yemeni scene. With the existence of a pro-Iran group that is capable to create chaos in the region, in the interest of Tehran, the chances of political solutions are shrinking. So there are more one scenario in the Yemeni scene based on the regional and international scene.
1) Scenario of US military strike against Iran:
The launching of a large or limited war on Iran will prompt it to respond and strike the Gulf States with missiles, especially the areas of power plants, oil exports, and trade and economy centers. In addition, its militias in the region will be used more violently in Yemen, which means that the Houthis will increase the targeting of cities, airports and installations in the Gulf, especially in Saudi, and the international corridor in Bab al-Mandab. Iran may have slept cells in southern and eastern regions that are controlled by the Yemeni government and the Arab coalition, or in areas that are ready to chaos in southern and eastern Saudi Arabia.
2) Scenario of tightening economic sanctions on Iran:
For Iran, tightening the economic sanctions to make its oil production “zero” is tantamount to a war against it. Therefore, it will not respond directly with a military action, but through its own militias, the Houthis in Yemen, who will target the cities, airports, civil and oil installations of the coalition countries. They will also try to explode the situation in areas under the control of the government and coalition, and to provoke chaos also in the Gulf.
3) Scenario of a new nuclear agreement between Iran and America:
This is the most powerful scenario and will put the Houthis, who have shown great loyalty to Iran, in a good position in the agreement, which means that their control and governance in the northern regions of Yemen will be supported with an international desire.
Separating Yemen from the repercussions in the region:
In conclusion: The procrastination of the coalition countries to end the battle with the Houthis on the ground, and the plan of some parties in the coalition to achieve their own strategic and security interests in Yemen, complicated the political, humanitarian and military situation.
By pursuing the three scenarios, the Saudi Arabia dependence upon a US military strike on Iran to subjugate the Houthis is futile, especially when the ambition of the Houthi group and Iran is not just to control Yemen, but to dismantle the Gulf states and control the oil areas and the holy sites so that Tehran can be the leader of the Islamic world.
Therefore, the Arab states, led by Saudi Arabia, have a little chance of victory in Yemen through defeating the Houthis militarily. Otherwise, the survival of the Houthis as a ruling force in northern Yemen, whatever the scenarios of the American-Iranian escalation, is a long-term threat to the security of the Gulf.
Iran's MPs don uniform of Revolutionary Guards in protest at US https://www.theguardian.com/world/2019/apr/09/irans-mps-don-uniform-of-revolutionary-guard-in-protest-at-us
 Crisis in the Gulf: ‘War by accident is real risk over Iran’ https://www.express.co.uk/news/world/1141099/gulf-crisis-us-iran-tensions-war-risk-donald-trump-mike-pompeo
 Watching alive press conference on Saudi al-Arabiya TV (21 June 2019)
 You can read the Abaad Center’s study on the Houthi movement and Iranian weapons in Yemen: “The terror of Iranian weapons”, “Houthi Forces Threaten Gulf Security” https://abaadstudies.org/news-59756.html
 CENTCOM: MQ-9 Reaper shot down over Yemen last week https://www.militarytimes.com/news/your-military/2019/06/16/centcom-mq-9-reaper-shot-down-over-yemen-last-week/
 Al-Jubair accuses Iran of being behind attacks on two oil pumping stations the belong to Aramco https://www.aa.com.tr/ar/1479700
 EU Diplomat Discusses Yemen in Tehran https://financialtribune.com/articles/national/98470/eu-diplomat-discusses-yemen-in-tehran
 Read the US initiative in the Abaad Center’s study “Difficult Peace for Yemenis...Could it be born in Sweden Consultations? https://abaadstudies.org/news-59787.html