Saudi Arabia's recent military assault on Yemeni rebels is the first time in almost 20 years that the kingdom has put its armed forces into play, a move meant to send a strong signal about the limits of Saudi patience, according to outside observers. "Saudi Arabia has always been politically and militarily timid in projecting its power," said Abdulkhaleq Abdullah, a political scientist at UAE University in Al Ain. "This is the first time [in recent memory] it is doing it - and it is sending a strong message - to show everyone else that it can't be pushed around too much." At the same time, questions are being posed about what the Saudis' long-term objectives are and how they will contain the rebel threat along their porous border with Yemen once the current military operation is halted. The Saudi operation appeared "motivated by a desire to hit back rather than a longer-term and thought-out strategy", Kristian Ulrichsen, a Kuwait research fellow at the London School of Economics, wrote in an e-mail. "I do not think the Saudis would be well advised to get involved in the fighting in Yemen," he wrote. "The country is rapidly becoming a failed state and the basic legitimacy of the - government is being contested both by the Houthi and by the southern secessionists." Gregory Johnsen, a Yemeni expert at Princeton University in the United States, also raised this issue. "For me the big question is how does this end for Saudi Arabia?" Mr Johnsen wrote on his blog, Waq Al Waq. "What happens when al Houthi [rebels] or tribal fighters retaliate by killing more Saudi troops, do the Saudis then retaliate and strike back again at the Houthis this time deeper into Yemen?" The Saudi intervention, Mr Johnsen added, did not appear to be "something that has been well thought out in Saudi Arabia". The Saudis have said they launched their military operation last week in response to "infiltrators" from Yemen who entered the Saudi territory in the area of Jebel al Dukhan, or Smoke Mountain, and attacked a Saudi border patrol, killing one and wounding 11. The mountain is smack on the border, with one side in Yemen and the other in Saudi Arabia. The Saudis used air power and ground forces to dislodge the rebels, claiming success in that on Sunday. They denied entering Yemeni territory. News agencies in the Yemeni capital of Sana'a, however, reported that diplomatic and military sources backed up claims by al Houthi rebels that the Saudi air force had struck at their camps inside Yemen. The Saudis have not officially addressed that claim, though a government adviser told news agencies on Thursday that the Saudi air force had been striking rebel positions since Wednesday. In 1990-91, Saudi Arabia was a major player in the US-led military coalition that ejected Iraqi forces from occupied Kuwait. But it has seen little or no military action since then despite the increasingly volatile conditions that have emerged in this part of the world. The US invasion of Iraq set off a bitter civil war in that country. Afghanistan and Pakistan are beset by terrorist actions in the heart of their major cities. And Iran's belligerent foreign policy towards Saudi Arabia added to the tensions. Now comes Yemen, which is "very critical for security" by virtue of its position as the "backyard" of the Gulf Co-operation Council, Mr Abdullah said. There is growing international and regional concern over Yemen's deteriorating situation. Besides the northern rebellion, the poverty-struck country is facing a secessionist movement in the south, worsening economic conditions, and a newly aggressive branch of al Qa'eda. Mr Ulrichsen noted that the Saudi military operation may end up generating increased GCC support for the Yemeni president, Ali Abdullah Saleh, if it "serves to concentrate the minds of GCC decision-makers on the Yemen issue, which I get the impression they would rather wish away rather than have to tackle". Yemen's problems are so huge that the GCC does not know where to begin to address them and so it opts for "the strategy of attempted containment", trying to keep Yemen's problems inside Yemen, he wrote. This strategy involves moves like Saudi Arabia's announced intention to build a border fence. But given the resurgence of al Qa'eda in the Arabian Peninsula, "Yemen is the number one security issue facing the GCC, not just in the short-term but in the medium- and quite possibly in the long-term as well," Mr Ulrichsen wrote. cmurphy@thenational.ae