The constant debate in terms about Israel is about whether any given act it takes is done to "preserve Israeli security" or "maintain the occupation". The answer, of course, is "both". Or more accurately, "either". Do they maintain the occupation? Yes. Do they protect Israel from real, extant security threats? Also yes. Israel has legitimate and illegitimate objectives, and the same actions can plausibly advance either. It is often impossible to tell which is the "real" motive from afar. The odds are, it is a mixture of each.
Take the three companies that the PCUSA may soon divest from: Caterpillar, Motorola, and Hewlett-Packard. Caterpillar sells armored bulldozers to Israel. Motorola runs cell phone networks in the settlements. And Hewlett-Packard provides information technology to the Israeli navy.
Caterpillar's bulldozers are sometimes used to build Israeli settlements, which is bad. Sometimes they demolish Palestinian houses because these houses are built "illegally" (in quotes because the process for Palestinians to gain building approval seems to be deliberately arcane and Kafka-esque), which is also bad. Sometimes it's because these houses are being used as bases for terrorist activity and firing, which is good. Sometimes it's to do normal construction activities inside Israel, which is good. When Caterpillar operates in Israel, it advances all these possibilities at the same time. If it withdraws from Israel, it retards all these objectives. It is true that we can sometimes clearly distinguish between good and bad usages -- but not always: demolition of a Palestinian house on claims that it is being used to smuggle weapons or as a firing post for terrorist will likely be met with skepticism by pro-Palestinian activists claiming it is gratuitous punishment -- we really have no way of knowing who is telling the truth from afar.
Motorola provides cellular technology to settlements, and settlements are illegal. Is that bad? I suppose, though it's unclear why this is different from companies which sell, say, food to settlers. Motorola also apparently provides some weapons technology (such as bomb fuses), and again, one can point out that the IDF's capacity to deliver lethal force can be used either to "protect Israel" (good) or "maintain an occupation" (bad). And one also points out that these are indistinguishable from afar. That Israel has an effective military by definition means its military is capable of pursuing both legitimate and illegitimate objectives. Trying to cripple that military means the opposite -- it would weaken both Israel's ability to maintain an occupation and it's ability to defend itself. It's difficult to disentangle these from one another.
Hewlett-Packard is perhaps the toughest case to justify. HP provides technology to Israeli Navy. To the extent this debate is about the settlements, HP is irrelevant -- Gaza has no settlements and the West Bank isn't on the water. Rather, HP is presumably being indicted because of the navy's efforts in placing a blockade on Gaza. I'm not convinced the blockade is illegal at all (it seems to fall inside the rules laid out by the San Remo Manual on International Law Applicable to Armed Conflicts at Sea, and most of the arguments against its legality either don't cite any legal arguments at all, or, as in the case of the UNHRC's report, made me embarrassed to share the profession of "attorney" with them). Of course, I also don't care about international law anyway -- so the blockade may still be wrong. In any event, the point is more or less the same: a blockade both can restrict the flow of necessary goods into Gaza (bad), and restrict the flow of weapons into Gaza (good).
A large part of why the bulk of the Jewish community is so uncomfortable with divestment from these companies is that they are unconvinced the divesters are putting any moral weight on the other side of the ledger. That is to say, while I say that Motorola simultaneously is enabling "good" (enabling Israel to defend itself) and "bad" (enabling Israel to maintain an occupation), the divesters don't consider the former to be "good" at all. It's either "irrelevant" or perhaps even "bad". This is particularly so with HP, which arguably isn't doing anything wrong at all -- it is not supporting the settlements at all. But regardless, the point is that there are two sides to the ledger, and it's not clear that even legitimate Israeli interests are being taken to account -- indeed, whether it is acknowledged that Israel has interests capable of being characterized as legitimate at all. In essence, it's the same problem in reverse -- the same tactics could plausibly advance legitimate (end the occupation) and illegitimate (end Israel) objectives, and it is impossible to tell from afar which is which.
So what does one do? In essence, the problem is one of trust -- all parties have ample reason to distrust one another, and little way of verifying which moves are legitimate and which ones are aggressive -- they tend to look the same. So I tend to focus on two, seemingly contradictory ambitions: (1) Rebuilding trust and (2) Making it so parties don't have to trust one another. The first is obvious -- mistrust significantly diminishes the range of actions one party can take without provoking the other. So in order to get things done, there has to be space for political action to breathe. That means listening to the other's concerns and claims of serious threat, even if one thinks they're unfounded. I don't think that Israel secretly harbors a desire to maintain control of Jericho forever, but I understand why Palestinians worry about it. And so Israel should behave in ways that alleviate that concern, and be mindful of how their actions interact with that lens upon Israeli motivations. Likewise folks operating from a pro-Palestinian perspective -- they may be absolutely confident that they're totally incorporating Jewish interests and concerns, but Jews seem convinced of the opposite. They have to take account of that fact, rather than engaging in further inflammation. This is the general project of groups like OneVoice, and why they are worthy of your support.
The second proposal is less romantic, but in some ways more important. Israelis and Palestinians don't trust one another. They don't think the other has their best interests at heart. Each are probably, at least to some degree, right about that. But right now they have to trust on another, because they're enmeshed in a relationship of mutual dependency -- both have to take actions predicated on what they believe the other will do. That is one reason why a two-state solution is not just the best solution but also, as Ziad Asali of the American Task Force for Palestine reminds us, is the only one that will ever work. A situation where Israelis and Palestinians are regularly in a position to influence the other's lives is a situation that will likely be characterized by strife, discord, and probably violence. So the goal should be to extricate the warring parties from one another as soon as possible.
This also, in part, is why I do not support a demilitarized Palestine. Part of the reason is simply because I want Palestine to have a monopoly on violence in its territory (if the PA doesn't have guns, then only Hamas will have them). But in part, it's also because I want Palestine to be in a position where it doesn't need to trust Israeli good intentions because it is capable of defending itself. For the same reason, I support Israel having a strong military (including a strong navy). Israel has a great many people who claim to want to destroy it. If Israel is militarily weak, it has to take those threats extremely seriously (in neorealist terms, it has to act aggressively on turn one because it can't guarantee there will be a turn two). If Israel is militarily strong, it can afford to take more risks and concessions because if its goodwill is exploited, it can rest confident its ability to utterly demolish whoever it is that was dumb enough to cross them. Power doesn't guarantee cooperation, but it creates the conditions by which cooperation is possible, because it makes it so that losing once doesn't mean losing everything. And that same logic is why, ultimately, empowering Palestine is the largest step in making Israel secure -- and vice versa.