Jews worry. One can argue if those of Israel worry more than those overseas, and who has the best reasons for worry.
Recent headlines have featured political pressures more than physical threats to Israel's existence.
A realist should applaud the turn. Most of the realists here are Jews, and any sign of applause is not apparent in the sounds of oy gevalt. Our Sephardi cousins have learned enough Yiddish to employ the expression.

Palestinians and their friends threaten on a daily basis to approach the UN, the International Criminal Court, and other forums to censure Israel and impose sanctions. 
Palestinians of the West Bank are most active on the political front. Their Gazan antagonists are still claiming victory in last year's violence. Clearing the rubble and rebuilding has barely begun, but they are adding to their military infrastructure, and threatening another round. 
We have just passed through a confrontation in the International Football (soccer) Federation (FIFA). Optimists describe it as Israel's slam dunk. Pessimists see it as a squeak, leaving behind a committee to examine Israeli actions on matters of football, which may have teeth, or may be nothing more than lip service. The pessimists see the confrontation on football as something that will repeat itself in international bodies dealing with the Olympics as well as individual sports.
Also in high gear are campaigns to boycott, disinvest, and sanction Israel's economic, scientific, and academic activities. Some of these focus narrowly on what occurs in the West Bank over the 1967 lines, and some focus on activities throughout Israel.
Optimists emphasize that Palestinians come to all these confrontations with dirty hands. That's an expression used in  court, against an individual or organization who brings suit, but is tainted by the same behavior involved in the accusation against others. 
The notion of Palestinian dirty hands pertains most clearly to whatever the Palestinians want to include in a case they would bring to the International Criminal Court. The Palestinians' violence against Israeli civilians, easily documented as encouraged or endorsed by officials of the Palestine National Authority, including incitement in education and other violations of existing agreements, can produce counter suits brought by Israel.
The record of Palestinian action in the International Football Federation suggests the line of defense Israel would take in the case of the Olympics and other sporting organizations.  Israeli officials justified actions against Palestinian football players on account of the players' involvement in terror or espionage. Palestinian blanket charges of "racism" may play well among leftists already on their side, but do not measure up to the ethnic integration of Israeli athletics, and action against players or fans who direct racist jibes at Arab players or teams from Arab towns.
Efforts to boycott Israeli universities, or to pressure entertainers to avoid performing in Israel have had some success, but come up against Israeli and overseas Jews who are prominent in the relevant fields, and work against the boycotts. Jewish students at several prestigious American colleges may suffer more from boycott efforts that spill over to anti-Semitism than students or faculty in Israeli institutions. 
Israel is most vulnerable against actions focused on its activities over the 1967 lines, i.e., settlements in the West Bank, including neighborhoods of Jerusalem established since 1967.
Israeli assertions of operating within international law--due to the unsettled status of land that Jordan controlled from 1948 to 1967--have not gotten significant support from international bodies. A host of resolutions and comments of leading figures have accused Israel of violating international law by settlement and other activity over the 1967 line. 
We hear different things from Barack Obama.
On the one hand, he indicates that both Palestinian and Israeli officials have resisted efforts toward the two-state solution.
On the other hand, he indicates that it is increasingly difficult for the United States to hold off pressure on Israel when there is no movement toward the two-state solution.
On the side of ignoring the international clamor is the response of Gaza to Israel's withdrawal of settlements in 2005.
That Palestinians are harming Palestinians no less than Israelis by their campaigns against economic enterprises in the West Bank does not seem to bother the Palestinian leadership. Israeli factories have closed, putting West Bank Palestinians out of work, with Israeli entrepreneurs looking to Jordan and elsewhere for more accommodating opportunities suitable to low wage, labor intensive industrial production.
There seems little value to the threat of leftists (Israelis, overseas Jews and others) that Israel will have to absorb the Palestinians of the West Bank if there is no progress toward a Palestinian state. The essence of the threat is that a major addition of non-Jews may come sooner or later to overwhelm the Jewish majority of Israel, and turn the country into something like Lebanon. All that would happen sooner if world opinion or international organizations managed to add the Palestinians of Gaza to what is now Israel.
The emptiness of these threats derive from Israel's capacity to say no, and the lack of will or capacity of international organizations to force the absorption of the entire West Bank and Gaza.
The emptiness of Palestinian threats to dissolve the Palestine National Authority (PNA) and require Israel to take charge of the West Bank and/or Gaza also derives from internal Palestinian realities. The livelihood of well connected Palestinian families depends on the continued existence of the PNA. Without the Palestinian authority exercised over Palestinian areas of the West Bank and Gaza, those families would lose their jobs and economic concessions that bring them profit from control over the imports of branded consumer goods, the operation of cell phone services, the supply of tobacco, gasoline, and other commodities.
None of the above allows the Jews of Israel to relax and enjoy the advantages of a decent standard of living and--especially in the Judean Mountains and Galilee--good weather. Political threats are more desirable than the constant threat of high level military confrontation, but require political efforts to counter the threats or to limit the damage. 
Israel is not without advantages. While Palestinians have succeeded in recruiting numerous overseas Jews and some Israeli Jews to their causes, there appear to be greater efforts among overseas Jews to counter what they see as threats against Israel that are unjust, and rebound against themselves via a generalized anti-Semitism.. It is not difficult to express charges of anti-Semitism against campaigns directed against a state whose practices outshine by far on just about every dimension what is available to Palestinians living under Palestinian regimes in the West Bank and Gaza, and among the citizens of every other Muslim state. Charges of Apartheid come up against Israeli university students who are Arab, ranging from 15 to 35 percent, depending on the campus.
While thinking about political threats, we should also remember Iran, Hezbollah, Hamas, ISIS and other varieties of aggressive Islam. However, not even Jews can think about everything all the time. Moreover, those baddies are spending most of their energy fighting one another.