Last week the judicial authorities in Cairo announced that they had arrested members of a Hizbollah cell and accused the Lebanese Shiite party of threatening Egypt’s national security. In a televised address, Hezbollah’s secretary general, Hassan Nasrallah, admitted that one of those in custody was a party member working to rearm Palestinians in Gaza. However, he added, no one was trying to undermine Egyptian security. Both accounts told us little about what is really going on.

When Nasrallah owned up to the arrest of one of his cadres, he deflected attention away from the fact that by setting up arms networks in Egypt, Hizbollah and behind it the party’s main sponsor, Iran, put themselves in a better position to manipulate Egyptian stability. After all, while those weapons may be destined for Palestinian groups, what is to prevent their distribution to organisations opposing Egypt’s regime?

What has happened in Lebanon since 2006 is instructive in this regard, and must be high in Egyptian minds. During that period, Hizbollah effectively mounted a coup against the Lebanese system. While the results were mixed, the party managed to impose a red line that neither its domestic adversaries nor the Lebanese state will dare cross again in order to disarm Hizbollah and challenge its political and military autonomy inside Lebanon. From a “resistance” movement initially focused on liberating South Lebanon, Hizbollah has morphed into an organisation with the ambition of holding the commanding heights of the country, as well as of playing a regional role on behalf of Iran.

Why 2006? In the aftermath of the summer war against Israel that year, Hizbollah started a campaign to reverse what had occurred in 2005, when international pressure and popular demonstrations in Beirut forced a Syrian withdrawal from Lebanon following the assassination of the former prime minister, Rafiq Hariri. Hizbollah viewed Syria’s departure with trepidation, as it removed the primary defender of its freedom of action. The summer war was a turning point. While Shiites suffered terribly from Israeli attacks, Nasrallah saw an opening to turn the tide against his Lebanese foes, and Syria’s, who held a majority in parliament.

Once the war ended, Nasrallah declared a military victory against Israel, then demanded veto power in the government for the Hizbollah-led opposition. Given that the president and parliament speaker were close to Syria, Hizbollah’s ability to also shape the government’s agenda would have crippled the anti-Syrian majority, known as the March 14 coalition. When the majority refused, Hizbollah began a sit-in in Beirut’s downtown area, kicking off 18 months of protests that carried Lebanon to the brink of civil war. In May 2008, the Siniora government took a pair of decisions that Hizbollah interpreted as efforts to inhibit the party. Nasrallah sent his gunmen into western Beirut and other areas to force the government to back down. It did, and the result was an accord signed in Doha granting Hizbollah and its allies veto power as well as a favourable law for parliamentary elections scheduled in June. Violence paid off.

The confrontation in Lebanon was followed by the conflict in Gaza early this year. There, Iran and Syria proved that they could exploit a local ally, Hamas, to undermine the credibility of both the Palestinian Authority and Egypt. Hamas thwarted Egyptian efforts to extend the truce in Gaza, and Hizbollah followed at the height of the fighting with Israel by accusing Egypt’s leadership of virtual treason for keeping the Rafah crossing closed. Hizbollah and Hamas had never been used so aggressively by Iran and Syria in a head-on assault on Egypt. The Gaza war isolated the so-called Arab moderates, whom many Arabs saw as complicit in neutralising what they considered legitimate Palestinian resistance.

More ominously, Lebanon and Gaza showed that Iran is trying to take decisive advantage of the weakness of the Arab state system, so that it might play a dominant role in the Middle East. This prompted the Saudi monarch, King Abdullah, to reconcile with Syria in January, and to sponsor Egyptian-Syrian reconciliation, his aim being to break Damascus away from Tehran. The Saudis want to put Syria’s president, Bashar Assad, on the spot so that he will have to either side with Iran or with his Arab brethren. Expectations aren’t high in Riyadh that this scheme will succeed, but the idea is that if Syria remains a strategic ally of Iran for much longer, it will be easier to isolate regionally afterward.

That’s the context for Egypt’s tension with Hizbollah. It was not surprising that Iranian officials publicly condemned Egyptian actions. More revealing, however, was that the Syrian daily Al Watan did much the same thing. The paper is owned by the cousin of Bashar Assad, suggesting that the Syrian-Egyptian rapprochement is already fraying. In Lebanon, meanwhile, as parliamentary elections approach, the Saudi-Syrian understanding, while it has calmed the political atmosphere, has not warmed relations between Hizbollah and its leading rival, the pro-Saudi Future movement – in other words between Shiites and Sunnis.

There is growing fear in many Arab states that Iran, directly or through the groups it finances, is making dangerous inroads into their societies. This has been the case in Lebanon and Egypt, but Saudi Arabia and Bahrain also worry about Iranian influence over their own Shiite communities. Iran’s considerable sway in Iraq, which comes as the Obama administration prepares to withdraw American soldiers from the country, also provides little reassurance for the Sunni-dominated Arab political orders. Syria remains an unknown quantity, but it is very unlikely that Assad will break with Tehran if he feels that it retains the initiative regionally.