The Israel-Iran standoff, in which Israel has long signaled its willingness to strike suspected Iranian nuclear sites if they come too close to producing a weapon, got a sort of very-small-scale dress rehearsal on Wednesday. The Israeli air force attacked a target inside Syria, Tehran's closest ally, which set off the expected condemnations (from Syria, Iran, Russia and the Lebanese militant group Hezbollah) and fears of reprisal.

Both Israel and Iran will likely be observing the fallout from the attack closely, trying to determine what it might say about how an Israeli attack on Iranian nuclear facilities would play out in the region. It's too early to say what, if anything, they could learn. But the possibility that they might extrapolate lessons about a potential Israel-Iran conflict gives added significance – and added risk – to every action and reaction in the coming hours and days.

Because Israel can't know for sure how Tehran and regional leaders would respond to a strike on Iran, its perceptions of their likely reactions could play a big role in determining whether or when it actually attacks. Tehran, for its part, is likely to pace its nuclear program in part based on what it believes it can get away with before prompting an Israeli or U.S. strike. Israel's attack in Syria, then, could be an opportunity for both Israel and Iran to test the other's will and to see whether they're able to change the risk-reward calculus.

As Iran has continued to grow its nuclear program, Israel – and the United States – have warned Tehran against taking what they see as steps toward a nuclear weapon. Iran insists its program is peaceful and a national right; Israel says the world must declare a "red line" beyond which the facilities will no longer be tolerated. Their positions are untenably contradictory, and both countries appear to be preparing for the possibility of a conflict, which would presumably begin with an Israeli and/or U.S. airstrike on Iranian facilities. Meanwhile, Iran appears to be doing what it can to continue or even accelerate the program, and Israel what it can to slow it, though both have been careful to avoid open war.

A sort of psychological conflict has developed between Israel and Iran, a war of signals. Tehran wants to demonstrate to Israel that a strike would be too costly and too ineffective to be worthwhile -- for example, because of a hypothetical counterattack from the Lebanon-based militant group Hezbollah and the Gaza-based Hamas. Israel wants to demonstrate that its will – and its defenses – are unshakable, so Iran might as well just give up on the program now.

The Israeli strike on Syria could allow both Israel and Iran an opportunity to reiterate those points, even if only through rhetorical or implicit threats, to shape the other's thinking. Is Israel bluffing about a unilateral strike on Iran, or would it really go ahead on its own? How much is Iran willing to risk for its nuclear program? In the event of a strike, would Iran throw all its weight into a counterattack or would it recognize the futility of all-out conflict?

It's been a long and complex game of threats, counter-threats and, yes, possibly bluffs. But that only adds to the interest that each side has in, first, proving to the other that it will follow through on its threats and, second, sussing out whether or not its opponent is bluffing. And that's why each will probably be watching the other so carefully for its response to the strike against Syria. Each has an interest in using this as an opportunity to deter the other by behaving as toughly as possible.

But that's where it gets really complicated. A big part of the Israel-Iran dance has been about avoiding all-out conflict. Some of the dangers that have likely kept Israel and Iran from actually seeing through their threats so far – the risk of unwanted escalation, of civilian casualties, of a costly fight that would ultimately strengthen hard-liners in one another's capitals – are also present in the Syria strike. Just as both sides have an interest in flexing their muscles to deter the other, so, too, are they careful about not needlessly provoking the other to violence.

The difference between Wednesday's strike and a hypothetical attack on Iranian nuclear sites would, of course, be substantial. Israeli jets would have much farther to go, probably requiring the support or at least acquiescence of the states they would have to fly over, such as Saudi Arabia. The operation would also have to be much larger in scale, given the number of targets, their size and the fact that they are believed to be under hardened facilities. And the standoff over Iran's nuclear efforts has become so fraught, layered by the game theory of nuclear deterrence and by years of regional and global politics, that the calculus behind an Israeli cross-border strike on a Syrian military target would be far more straightforward.

In the end, perhaps Israel and Iran will both be too worried about unnecessary escalation to do much more than make threats. With Hezbollah's forces spread unusually thin by the Syrian civil war and  Hamas, in the Gaza Strip, possibly still recovering from its recent conflict with Israel, Iran's proxies are not at their strongest. And Israel, for its part, would doubtless prefer that Syria's conflict – and particularly any chemical weapons that the military might hold – stay in Syria. Still, it will be hard for the Middle East's leaders to avoid seeing parallels between Wednesday's strike and the possible Israeli strike on Iran that they have been anticipating now for years.