With Decisive Storm airstrikes showing no signs of abating, and with some reports suggesting that as many as 40 people were killed when bombs struck a refugee camp near Haradh, many suspect the violence in Yemen is set to escalate meaningfully in the days and weeks ahead with Saudi Arabia preparing to launch a ground invasion in the expanding effort to debilitate the Iranian-backed Houthi rebels who toppled the US-supported Yemeni government. The bombing raids by the Saudi-led coalition have persisted for five consecutive days in Sanaa and al-Hodeidah where air strikes targeted anti-aircraft installations. The Yemeni foreign minister denied that the coalition was responsible for the death of refugees and instead placed the blame on rebel artillery fire. Via Al Arabiya: Yemen’s foreign minister blamed Iranian-allied Houthi fighters for an air strike on a camp for displaced people and refugees in northern Yemen that killed at least 45 people on Monday, denying any link to Saudi-led military operations. Riyadh Yaseen was speaking to reporters in the Saudi capital Riyadh. He said the explosion on the camp was not from Arab coalition forces but by “artillery strikes” by the Shiite Muslim Houthis. Meanwhile, in what is perhaps the surest sign that a ground invasion is in fact in the offing, the Saudis are out saying there’s currently no need to put boots on the ground: https://twitter.com/hashtag/BREAKING?src=hash!function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0],p=/^http:/.test(d.location)?'http':'https';if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src=p+"://platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs");: Saudi-led coalition spokesman: No current need to send ground troops to https://twitter.com/hashtag/Yemen?src=hash!function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0],p=/^http:/.test(d.location)?'http':'https';if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src=p+"://platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); http://t.co/mhNcLhJztF — Al Arabiya English (@AlArabiya_Eng) https://twitter.com/AlArabiya_Eng/status/582944459551166464!function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0],p=/^http:/.test(d.location)?'http':'https';if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src=p+"://platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); And as CNN notes, a ground war with the Houthis is likely to be an arduous, bloody affair that could further imperil Saudi Arabia’s southern border: But if the coalition takes the fight to the ground in Yemen, the consequences could be severe. Houthis are battle-hardened guerrilla fighters and could cross into Saudi Arabia. They've already threatened suicide bomb attacks inside Saudi Arabia… Saudi Arabia and Egypt have both talked about the possibility of putting boots on the ground. On Saturday, Yemeni Foreign Minister Riyadh Yaseen said he expected coalition troops to be in Yemen within days. Saudi leaders have said that if troops do go in, they won't leave until they have degraded the Houthis' ability to fight. The Houthis are apt guerrillas. A fight on the ground could prove bloody and lengthy. Unfortunately, it now appears that this “bloody and lengthy” conflict just got a little closer to becoming reality as Reuters reports that Houthi rebels have gained access to a military base at the Bab el-Mandeb Strait, the 4th largest oil-shipping chokepoint in the world. As CNN notes, “that passage that is the only access from the Arabian Sea to Egypt's Suez Canal.” Here’s more via Reuters on the rebels' advance... Fighters from Yemen's Houthi militia on Tuesday entered a coastal military base overlooking the Red Sea's strategic Bab el-Mandeb strait, local officials told Reuters. Soldiers of the 17th Armoured Division in the Dabab district in Yemen's southwestern Taiz province opened the gates to the Houthis, whose military advance has been challenged by six days of Saudi-led air strikes. Yemen's Houthi rebels enter coastal military base on Bab el-Mandeb strait, watch details on JAAG TV pic.twitter.com/YyjqsS47b9 — JAAG TV (@JaagAlerts) https://twitter.com/JaagAlerts/status/582974936941260800!function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0],p=/^http:/.test(d.location)?'http':'https';if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src=p+"://platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs"); ...and on the implications for the regional balance of power... The collapse of Yemen as a political reality and the power of the Houthis will enable Iran to expand its presence on both sides of the Bab el-Mandeb, in the Gulf of Aden and in the Red Sea. Already discrete numbers of Iranian naval vessels regularly sail these waters," J. Peter Pham of U.S. think tank the Atlantic Council said. Analysts say Houthi forces do not themselves have the maritime capabilities or the interest to target the Bab el-Mandeb, while warning of Iranian influence. "If the Iranians were to gain access to a de facto base in some port or another controlled by the Houthis whom they have aided in the latter’s fight, the balance of power in the sub-region would shift significantly," said Pham, who also advises U.S., European and African governments… Any closure of Bab el-Mandeb, Arabic for "Gate of Tears" due to its precarious navigation, would close off the Suez Canal and the SUMED pipeline that connects to the Mediterranean and supplies oil to southern Europe. "If an escalating conflict results in the closure of the Bab el-Mandeb Straits, tankers from the Persian Gulf would be unable to reach the Suez Canal and the SUMED Pipeline, diverting them around the southern tip of Africa, a journey of at least 40 days," said shipping analyst Natasha Boyden with MLV & Co. For their part, SocGen was out on Monday opining that the chances of a disruption to oil shipments occasioned by the conflict in Yemen were relatively slim, but the following commentary sheds some light on how important the strait truly is, on who is there patrolling the waters, and on what role Iran may play in enhancing the Houthi’s maritime capabilities: The only possible issue, in our view, is the Bab el-Mandeb Strait (see map above). This is a chokepoint between Yemen and Djibouti that connects the Red Sea with the Gulf of Aden and the Arabian Sea. According to the US EIA, 3.8 Mb/d of crude oil and refined products flowed through this waterway in 2013 in both directions, north towards Europe and the US and south towards Asia. More than half the traffic, 2.1 Mb/d, moved north to the Suez Canal and the parallel Sumed pipeline. At its narrowest point, the Bab el-Mandeb Strait is only 18 miles wide, limiting tanker traffic to two 2-mile-wide channels, one in each direction. However, because of their strategic nature for oil trade and other commerce, the Gulf of Aden, the Bab el-Mandeb Strait, and the Red Sea are heavily and permanently patrolled by US, NATO, and other allied naval forces. The Iranian navy also maintains a regular presence. Last week, Egypt, which is part of the Saudi-led coalition, sent 4 additional naval ships to the Red Sea… Houthi land forces are reportedly well trained and equipped. However, for them, as for many similar militia groups, it would be a very big step to add a maritime capability. Hypothetically, Iran could help them add such a capability. However, at this time, Iran’s support may be limited to financing. It is not clear from reports if Iran is providing equipment and training to the Houthis. Iran is not overtly involved militarily, in the same sense that they have boots on the ground in Iraq and Syria (for example). To carry the hypothetical scenario forward, Iran might, at some point, be able to help equip and train the Houthis to carry out attacks at sea using small, fast boats packed with explosives, acting alone or in swarms. This is a capability that Iran itself has. Finally, Reuters is reporting heavy rocket and artillery fire along the border as the Hadi government begs for a ground incursion: Residents and tribal sources in north Yemen reported artillery and rocket exchanges along several stretches of the Saudi border. Explosions and heavy gunfire were heard and Saudi helicopters flew overhead, they said. In the southern port of Aden, Houthi fighters and allied army units pressed an offensive against forces loyal to Hadi, trying to capture the last remaining major stronghold of the absent president's forces. At least 36 people were killed when Houthi forces shelled Hadi loyalists in Aden. Jets from the Saudi-led coalition bombed Houthi positions near the airport. Hadi's rump government, now based in Saudi Arabia, is calling for Riyadh to escalate the air war into an invasion.