Governments - indeed most people - will defer to the simpler, easier solutions whenever possible. There's a good reason why the US hesitated before entering both world wars: they're messy, expensive and cost many, many lives. So, I don't entirely blame those who say, shouldn't Israel have continued to pursue peace before looking at military solutions? But, there's also a point where we say, the pursuit of peace is a stalling tactic to avoid an inevitable conflict, not a sincere goal in itself. Every administration wants to put off expensive, difficult conflicts until the next government.
Look, the truth of the matter is neither Israel nor the Arabs (including the Palestinians) are seeking peace, as such. 'Peace' was attainable many years ago. Jewish Zionists could have recognized the White Paper of 1939, allowed immigration to slow to a trickle, and accepted permanent minority status in Palestine - with whatever reduced privileges that might have entailed, and assuming the Jews already in Palestine weren't expelled. Likewise, the Arabs could have long ago accepted a Partition Plan (which would have given them a much larger state than any negotiations today might produce). And there were certainly other opportunities for peace squandered by both sides.
Today, the reality is that Israel demands first-and-foremost a) security and b) recognition. The Arab world wants a) the restoration of Arab honour (through Israeli acknowledgment of culpability) and b) reasonable compensation for those displaced by the wars of 1948 and 1967. 'Peace' will be the result of these demands being met.
It's also worth noting that many polls over the years, since before 1948, have maintained that most Palestinians are actually more interested in economic and social stability than independence or autonomy. They want normalcy, which is not an unreasonable demand. Yet, there has been a minority element within the Arab world for years which has persisted in making impossible demands to the detriment of their own people. When the international community accedes to the will of Palestinian extremists, they are essentially spitting in the face of moderate Palestinians who want their voices to be heard, too. But, as I said, this is the easy way out: listen to the guys with the guns, because the alternative is to try to understand and maneuver through the complexities of the Arab and Islamic worlds. Frankly, I blame Edward Said, but that's another story.