It's as good a theory as any.
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.
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.
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.
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.
(slight correction h/t CHA)