In the case of “Operation Pillar of Defense” in Gaza, there is another, perhaps more relevant, quote from Clausewitz’s On War:

If war is part of policy, policy will determine its character. As
policy becomes more ambitious and vigorous, so will war, and this may
reach the point where war attains its absolute form. … Policy is the
guiding intelligence and war only the instrument, not vice versa.

Apparently either Clauswitz hadn’t heard of Israel and Gaza (which may be forgiven) or Israeli decision-makers
haven’t read Clausewitz (which is harder to forgive), and it seems that
the “vice versa” Clausewitz cautioned against prevailed in Israeli
decision-making.
In fact, as just and justifiable as it is, this operation is a reversal
of Clausewitz: Policy seems to be the continuation of war. More
accurately, in the absence of policy, military results will create it.
This is abundantly evident in the cease-fire agreement, a loose and moot collection of understandings brokered by the US and Egypt. The agreement,
reached Wednesday night, highlights one point: Quiet will be answered
with quiet. A welcome conclusion, no doubt, but hardly a policy worth
the operation and the potential escalation it contained. The agreement
will probably have a limited shelf life, but more importantly, it is
almost identical to the one reached after “Operation Cast Lead” in 2008.
So what was the point? How is this serving a policy or shaping one
beyond the unintended consequence that Benjamin Netanyahu would rather
conceal? Israel recognized Hamas as part of a fragile security regime.
Call it realism if you want, but if that was the objective, it could
have been achieved without eight days of attrition and rockets.
It is worth revisiting Israel’s fundamental dilemma pertaining to
Gaza. Israel is faced with a relatively simple choice: Invade Gaza and
destroy Hamas, or accept Hamas and negotiate with it.
Toppling Hamas in Gaza requires a massive military operation:
essentially, a comprehensive conquest of the Strip, approximately twice
the size of Washington, DC and the most densely populated and arguably
unlivable place in the world. The implications are unequivocally dire;
it would require Israel to control Gaza for several years. Israel can do
this, but refuses to bear the consequences: economic, political, moral,
international and regional.
The second part of the equation is to open a dialogue with Hamas over a
long-term political accommodation, short of peace. With Hamas and the
Arab Spring being what they are, that is untenable.
Since both options are unviable, Israel may have various ideas, but cannot really have a strategy in Gaza.
There are at least fifty shades of gray areas that explain the absence
of a clear and coherent policy. What is inexcusable is the fact that
there is no long-term strategy. Before elaborating on this, it is
imperative to remember several truths about contemporary Gaza:

• No country in the world would tolerate the unprovoked, deliberate
  launching of rockets into its territory and against civilian population
  centers. The US would respond forcefully, probably massively, if rockets
  were fired from Mexico or North Korea. Russia would annihilate Latvia
  or Kazakhstan if missiles were fired at it. The distances are also of
  importance; Israel is attacked from the equivalent of the distance from
  Baltimore to Washington, D.C, or from Luton to central London. These are
  the long-range rockets Hamas is using. The shorter-range ones are fired
  from — get this for proportions — the Upper West Side of Manhattan to
  the Upper East Side, or from Westminster to Hyde Park Corner in London.
• Hamas is a fundamentalist Islamic organization whose very charter
  calls for the destruction of Israel and claims that the owners of
  Palestine are the Muslim waqf (religious endowment), rather than the
  Palestinians.
• Hamas controls Gaza for all intents, purposes and political
  considerations. That control, attained initially through elections and
  followed by a coup against the Palestinian Authority, has widened the
  disconnect between Gaza and the West Bank, controlled by the Palestinian
  Authority. The gap is political, cultural, economic, ideological and
  most pertinently: the disconnect puts a huge question mark over the
  viability and sustainability of a Palestinian State.

Given these facts, and in face of this dilemma, Israel had no real
option but to narrow the objectives of the military operation. In other
words, there is no political objective. This is a purely military
endeavor, sugar-coated with statements about “restoring deterrence.” In
and of itself, this is not necessarily bad. But even considering the
merits of such an operation, whether Israel has any game plan in mind
remains moot.
When you do not negotiate with the Palestinian Authority, when you
don’t consider the Arab League peace initiative (the “Saudi Plan”), when
you do not produce any creative diplomatic ideas to break the status
quo, you end up strengthening and legitimizing Hamas and weakening the
more secular, nationalist and moderate Palestinian Authority.
Hamas deserved what it got — and probably more — but the question
remains whether Israel achieved anything in the medium or long runs.
Ambassador Alon Pinkas was Israel’s consul general in New York,
adviser to Shimon Peres and chief of staff to Ehud Barak and Shlomo Ben
Ami. He is currently a fellow at the Israel Policy Forum (IPF).