Israel faces no end of threats and challenges, any one of which is capable of fueling endless discussion — not to mention anxiety — among Jews and gentiles around the globe. There is one challenge, however, that’s rarely discussed above a whisper outside Israel, because of its extreme sensitivity. You might call it the hidden Jewish demographic crisis: the population explosion among the Jewish state’s Haredi or ultra-Orthodox Jews, and the implications of that growth for Israel’s long-term survival.

When the exemption was first approved in 1948, it involved barely 400 men. Four decades later, in 1992, the Torah-study exemption was granted to 5% of that year’s conscription-age cohort of 18-year-olds. This year, 2007, the proportion reached 11%. In 2019, the exempted yeshiva students are projected to top 23% of the cohort, which is the proportion of Haredi students among this year’s first graders — the most straightforward predictor.

The figures are contained in reports issued in July by two Israeli government agencies. One, released by the army’s manpower division, simply states the proportions of conscripts and exemptees. According to the report, just under 24% of all 18-year-olds will be exempted from the draft this coming fall. Of those, 11% — close to half — will be excused because of Torah studies. The rest will be divided roughly evenly among Israelis living abroad, those with criminal records, medical deferments and those found “psychologically unfit” — by health or inclination — for military service.

Nonreligious exemptions have declined in recent years, but Torah exemptions have soared. The main reason is fertility: The Haredi community averages 7.6 children per woman, roughly triple the rate for the population as a whole, according to the Israel government’s Central Bureau of Statistics.

The demographic trend is demonstrated plainly in another report, prepared by the statistics bureau for the Ministry of Education. The report shows enrollment figures in Israel’s three separate Jewish school systems, the state-secular, state-religious (Modern Orthodox) and Haredi streams. In the 15 years from 1992 to 2007, the proportion of Jewish children attending state-secular elementary schools dropped to 55% of the total from 67%; in 2012 it is projected to fall to 51%. The percentage attending Haredi schools, meanwhile, went from 12.4% in 1992 to 26.7% in 2007 and a projected 31% in 2012. Modern Orthodox schools (whose graduates do perform military service) remain steady throughout at roughly 18%.

At some point in the late 2020s, if current trends continue, the percentage of Israeli Jews claiming army exemption due to Torah study will pass the 30% mark and continue climbing.

These figures don’t include the schools of Israel’s Arab community, which is almost entirely exempt from military service. The Israeli Arab birthrate is climbing, as well, although nowhere near the pace of Haredi increase.

Factoring in the Arab schools, Israel’s elementary-school population in 2012 will look like this: 41.7% state-secular, 13.5% state-religious, 17.4% Haredi and 27.4% Arab. Unless something changes drastically, Israel’s military draft pool will fall below 50% of draft-age youth by the year 2030 or soon after.

One can only pray that Israel reaches stable peace with its neighbors before it runs out of draftees.

But even peace will not solve the problem of Haredi men removed from the work force by their prolonged yeshiva studies. At present, just 30% of Haredi men participate in the work force. Almost half the Haredi population lives below the official poverty line. As the Haredi share of the population grows, pressure will mount on the tax rolls, the welfare system and inter-communal tolerance and civility.

Attempts have been made to integrate the Haredi community into essential aspects of Israeli society, but with little effect. A special Haredi unit of the army was created, shielded from contact with women soldiers and enriched with Torah study. So far it has drawn only a few hundred men. Most of them, ironically, are not Haredim but settlers, Modern Orthodox Jews who would serve in the army anyway, but prefer the stricter religious milieu of the “Haredi” units.

Efforts have also been made to amend the draft laws so that young Haredi men can hold jobs. The latest was floated in late July by Israel’s Finance Ministry. Past efforts have met fierce resistance from Haredi rabbis, who view Torah study as sublime and employment as a distraction. Ideally, the solution can be found through mutual compromise. Unfortunately, most of the compromising will have to come from the Haredi leadership, a group known for its uncompromising views in matters of faith.

The debate turns familiar categories of Jewish loyalty on their heads. We’re not accustomed, especially in the Diaspora, to the idea that those Jews who are most devoted to Judaism might constitute a threat to the Jewish future. The hidden demographic crisis is a wakeup call to all sides.