If Israel bombed a Sudanese munitions factory, as Khartoum alleges, the raid was part of its widening proxy war against Islamist militants in neighbouring Egypt which the Jewish state is reluctant to confront directly.
A huge explosion ripped through the factory near the Sudanese capital Khartoum on Tuesday, killing two people, with Sudan swiftly accusing Israel of sending four military planes to take out the complex.
The poor Muslim east African state, with its ties to Iran and Sunni jihadis, has long been seen by Israel as a conduit for weapons smuggled onward to the Hamas-ruled Gaza Strip, via the Egyptian Sinai desert.
With Sinai itself becoming a seedbed of al Qaeda-inspired cadres during Cairo's political upheaval, the Israelis now fear such arms could be used against them from within Egyptian territory. That puts Israel in a strategic bind, laid bare by the half-dozen guerrilla attacks it absorbed over the Egyptian border in recent months.
The countries' landmark 1979 peace accord precludes Israeli military action, whether preventive or retaliatory, in the Sinai, and Israel is highly unlikely to risk even a one-off breach given Egypt's unsympathetic new Islamist-led government.
Israel's response, government and military sources said, has been to hit first against those on Egypt's periphery suspected of links to the Sinai militants.
That has meant stepped-up up air strikes on Gazans accused of plotting operations in Sinai, and – to judge by reports from Khartoum – similar escalation in Sudan, to Egypt's south.
Israel has never confirmed or denied carrying out attacks on Sudanese targets. But Israeli defence officials admit placing a high priority on tracking arms trafficking through the country.
The monitoring, one retired official said, dates back to the previous government of Prime Minister Ehud Olmert, which waged a 2008-2009 Gaza war to crush Palestinian rocket fire and found itself fending off fierce censure abroad over the civilian toll.
Since early in 2009, shortly before the centrist Olmert was succeeded by the right-wing Benjamin Netanyahu, Sudan has accused Israel of carrying out several strikes on its territory. The sense of a far-flung covert campaign was further fuelled by the Israelis' alleged assassination of a senior Hamas armourer in Dubai in 2010 and abduction for trial of a suspected Palestinian rocket expert from Ukraine the following year.
Commenting tersely on Israel's strategy, the ex-official said it aimed to "stem the flow of arms (to Sinai and Gaza) without triggering major confrontations".
"This is all the more relevant today," the ex-official said, referring to instability in Egypt and surging Sinai militancy.
Foreign intelligence sources said Israel carried out a unmanned drone raid on a convoy south of Khartoum last month that destroyed 200 tonnes of munitions, including rockets, intended for Gaza.
Tuesday's blowing up of the Sudanese munitions factory was different to previous incidents, in that a state asset was hit. In a further suggestion of escalation by Israel, witnesses said the sortie was carried out by piloted fighter jets.
Amos Gilad, a senior Israeli defence official, made clear that Sudan should be considered fair game – an enemy like Hamas and Iran – and that Cairo's interests were also at stake.
"It is clear that it (Sudan) supports the smuggling of munitions, or it helps Gaza. In actuality, these munitions pass through Egypt, so it is endangering its major neighbour, Egypt. It harms national security because tomorrow these arms could also be used against the Egyptians," Gilad told Army Radio.
Sudanese Information Minister Ahmed Belal Osman declined to say whether any weapons from the attacked Yarmouk arms factory in Khartoum had ended up in Gaza, saying on Wednesday that only "traditional weapons in line with international law" were produced there.
A Swiss-published 2009 Small Arms Survey sponsored by several European governments found that Iran was a major supplier of light munitions to Sudan.
Khartoum has not said whether Iran was in any way involved in the factory that was bombed. A non-Israeli source briefed on the incident said the air strike focused on the main open area between the plant's main buildings, leaving open the possibility the target was specific personnel or production lines, rather than the whole complex.
Given the some 1,900 km distance between Israel and Sudan, some Israeli commentators saw in the alleged raid a warning to Iran, whose similarly remote nuclear facilities the Netanyahu government has hinted it could attack should diplomatic efforts to shut them down fail.
Alex Fishman, senior defense analyst for Israel's top-selling newspaper Yedioth Ahronoth, dubbed the Sudan raid a "live-fire practice run" for Iran.
But the Israeli ex-official, who has an extensive military background, was sceptical about comparing a fenced, open-air Khartoum factory with antiquated air defences to Iran's dug-in nuclear facilities.
The ex-official also noted the further difference between flying along the Red Sea toward Sudan, an international aviation corridor, to the prospect of Israeli jets reaching Iran through the unfriendly skies of Arab states like Jordan, Iraq, and Saudi Arabia.
"Israel isn't 'signalling' to Iran, just as it's not 'signalling' to the terrorists in Sinai," the ex-official said. "Whatever actions might be taken in Sudan are taken to counter a real, immediate threat."
Though attacks on Israel by Sinai jihadis have been mainly with small arms, there have been occasional short-range rocket launches and Israeli officials worry about possible attempts to down airliners with shoulder-fired missiles.
