After left-wing activists' hopes for a well-publicized clash with the Israel Defense Forces aboard the flotilla to the Gaza Strip were dashed, both sides are now working on Plan B: a fly-in.

So far, sensible Israeli conduct has prevented a violent confrontation with the flotilla activists. But the way things looked last night, the Israeli authorities' hysterical and disproportionate response to the airlift of pro-Palestinian activists may result in a different sort of clash, albeit a less violent one, at Ben-Gurion Airport.

The government and the security forces are normally criticized for not being sufficiently prepared - for negligence in readying to meet known threats, which usually ends badly. Thus it is hard to complain that the country is preparing excessively. Yet that indeed seems to be the case this time.

The fly-in, despite the mountains of words written about it over the past week, does not really pose a security threat to Israel. At most, it involves several hundred activists coming to Israel from friendly states, and all those countries conduct extensive security checks on flights to Israel. Thus the chance that any of these activists will manage to smuggle even a knife into Israel is remote. And a noisy demonstration at the airport or a mass lie-in in front of passport control would be a public relations stunt, not a substantive threat to the well-being of Israel's citizens.

The overreaction stems from the siege mentality that has taken hold over the past two years in the clash between the Netanyahu government and the campaign to delegitimize Israel in Europe. The previous high points were the Goldstone Report on the war in Gaza in early 2009 and the deadly clashes with activists aboard last year's flotilla. If the Turkish government, which is indeed hostile, was presented here as evil incarnate, it is not surprising that the activists at the airport are described as a clear and present danger.

To this should be added the permanent atmosphere of panic and confusion around Prime Minister Benjamin Netanyahu. Having already suffered two blistering reports by the state comptroller - on last year's flotilla and the Carmel fire - Netanyahu is taking no chances now. Nearly every move is weighed in light of the question, "what will the comptroller say," and that creates enormous pressure.

The third factor is institutional rivalry. The public security minister and the police commissioner are a little jealous of their colleagues, the defense minister and the IDF chief of staff. Why should they reap all the glory, getting photographed in front of the radar screens or examining the readiness of the forces? What does the navy have that the police does not?

The trouble, of course, is that over-preparedness may turn out to be a self-fulfilling prophecy. All the attention from the media and the police commissioner merely increase the chances that this will end with photos of the riot police beating a foreign activist unconscious appearing on the front pages of every European newspaper.

The preparations for this year's flotilla were conducted very differently, and that is due mainly to the commander of the navy, Maj. Gen. Eliezer Marom. It appears that deep in his heart, though he wouldn't admit it even under torture, Marom knows that the raid on last year's flotilla was not a huge success.

So this year, the navy prepared differently, emphasizing coordination and cooperation with the Foreign Ministry and the intelligence community. The result is that a series of events has pulled the rug out from under the flotilla organizers' feet: Turkey's government withdrew its support, the Greek government played hardball with the activists, and mysterious breakdowns happened to ships before they sailed.

The story of the flotilla is not yet over. Even though the activists have only two ships of any importance, scores of them are still in Greece trying to find a way to the Gaza Strip.

Israel's efforts to foil the flotilla, its enormous investment of man hours and resources, have been impressive. But if the purpose was to enforce the blockade of Gaza, how much effort could have been invested instead in stopping the real arms smuggling into the Strip?