In 2015, mass migration, whether it be of refugees from war-torn areas or simply job-seekers, became a leading issue in many Western democracies. In the United States, Republican presidential candidate Donald Trump is riding a wave of popular antagonism toward immigration. In Switzerland, the Swiss People’s Party, which demands limitations on immigration, won a decisive victory in the October elections. Immigration was also the focus of debate in the recent regional elections in France, to a considerable degree because of the November 13 terrorist attacks in Paris. Moreover, France is among the European Union countries seeking to formulate a uniform policy on migration, which pits principles of national character against humanistic values.As public awareness to the issue of immigration rose, the political systems in most Western countries, heeding public opinion, moved in a more conservative direction. Concern about a change in national character as a result of the significant extent of the phenomenon has fed this trend. Chancellor Angela Merkel’s remarks about her desire to “drastically reduce” the number of immigrants reaching her country thus signals a watershed in German immigration policy, after one million entered the country in 2015.For Israel, the issue of immigration has a known strategic significance, with far reaching consequences for the broader sense of national security. Israel is the only Western country with a land border with Africa, a huge “immigration exporter” to the West, and is very inviting to the many Palestinians residing illegally within Israel’s borders.Migration trends adapt themselves to the policies of the various target countries. A “softer” policy results in a stronger flow of immigrants, and vice versa, as evident in the examples of Sweden and Australia. Over the years, Sweden has adopted a liberal policy on immigration, which includes easily accessible welfare and integration conditions. Furthermore, Sweden grants permanent resident status to refugees or stateless persons after four years, and citizenship after a number of years of residency.It is no wonder that these conditions encouraged immigration to Sweden, and among European states Sweden granted the highest proportion of asylum requests (77 percent). In 2014, there were 80,000 requests for asylum, 50 percent more than in the preceding year, when Sweden announced that it would offer permanent residence to migrants from Syria, and in 2015, Sweden confirmed its acceptance of 190,000 immigrants. Thus, in recent years, Sweden has evolved from a homogeneous to a multicultural country, and has also criticized other countries in Europe for their tougher attitude toward immigration.Nevertheless, given the growing flood of immigrants over the Oresund Bridge connecting Sweden and Denmark, and in light of the many homeless people in city plazas, a change in the atmosphere with respect to immigration is visible. A legislative process was begun that made it possible to close the bridge and reinforce the personnel stationed at the passport control areas on the borders, and it appears that these measures have slowed the flow of immigration. Sweden’s prime minister, who only a few months earlier had said, “My Europe doesn’t build walls,” recently stated, “Sweden is no longer able to accept the high number of asylum-seekers we’re seeing today.”Australia provides a different example. Although a nation of immigrants, its tough policy features selective control of those entering its gates. Australia offers economic and social advantages, but its population is not large and it is therefore sensitive to dramatic changes in its national and cultural character.Early in the 21st century, after years in which many immigrants came to Australia, a Pacific Solution policy was adopted, whereby immigrants were transferred for “processing” to facilities on Nauru and Manus Islands. This policy, which deterred immigrants and reduced their number, was abandoned in 2007 (as a result of internal political developments), and the flow of those seeking legal asylum in Australia increased. In July 2013, Australia and Papua New Guinea signed a “Regional Resettlement Arrangement” (the PNG solution), whereby immigrants, assuming they were found to be entitled to refugee status, were transferred to Papua New Guinea. A facility on Manus Island was substantially expanded, and immigrants were sent there before being transferred to Papua New Guinea.If it is found that they are not entitled to refugee status, they remain in the facility, are returned to their country of origin, or are sent to a third country. As expected, human rights organizations have criticized this policy.The challenge for Israel Over the past decade, Israel has been challenged by large-scale migration from Africa, mainly from Eritrea and Sudan. Tens of thousands infiltrated Israel via the Sinai border in order to find jobs. With Sudan defined as an enemy country, and given the dire state of human rights in Eritrea, it was problematic to send the infiltrators back to their countries.Instead, measures focused on closing the border, deterrence and encouraging voluntary exit. In addition, agreements were signed with other countries in Africa making it possible to send infiltrators there, albeit on a small scale. Israel initially took no steps to halt the phenomenon, which led to a major increase in its scope. Several years later, it was decided that a fence was to be built on the Egyptian border, while the preventive and deterrent measures employed included the legal recourse of holding infiltrators in prolonged detention.An integrated policy was later introduced, designed to reduce the number of migrants in city centers and in Israel as a whole, and to encourage their voluntary departure. The monetary incentive for voluntary departure was increased, and infiltrators were transferred from city centers to Holot, an open detention facility. This policy began to yield results immediately after it was enacted in December 2013.In the first quarter of 2014, 4,000 migrants left Israel voluntarily, and infiltration by migrants was halted almost completely.However, the High Court of Justice held a hearing on the matter in early April 2014, and after the court struck down the law in September, the number of those leaving plummeted. A rather weak law was later enacted, which reduced the detention period to three months, which was only one month longer than the period already set stipulated in the Entry into Israel Law. Here, too, however, the court intervened: In 2015, for the third consecutive time, the length of time that infiltrators could be held in the detention facility was overturned. As a result, the entry of migrants into Israel resumed in the second half of 2015, although on a smaller scale.The question is whether the extent of infiltration in 2016 will grow following the erosion of these countermeasures. Egyptian policy is already having an effect on the issue. The proven link between the measures adopted (or not adopted) by a country and the scale of the infiltration should clearly be taken into account. A resolute policy is a barrier, while its erosion tends to encourage infiltration, at first in a few cases, followed by a growing tide.Infiltration from Sinai is not the only immigration challenge facing Israel. Fifteen years ago, Israel halted a large influx of Palestinians seeking to enter Israel on the basis of “family reunion” with Arab citizens.During the second intifada, security agencies became aware that many of the most severe terrorist attacks were being carried out by Palestinians who had gained entry to Israel in this manner. As a result, the government decided to ban family reunions and at the government’s urging, the Knesset enacted legislation forbidding family reunions, except for cases stated by law. This law survived a petition to the High Court by a margin of a single vote.An additional challenge facing Israel revolves around illegal residents and the possibility of a nonmilitary mass storming of its borders. Israel does not have adequate control over those coming from Palestinian Authority territory, and the Shin Bet (Israel Security Agency) estimates that there are 50,000 illegal residents in Israeli territory at any given time.More than a few terrorist attacks in the current wave were carried out by illegal residents, and the phenomenon of illegal entry by Palestinians cannot be stopped unless it is addressed effectively. Except for storming of the Israeli border by a mass of Syrians (of Palestinian origin) during the Nakba Day events in June 2011, Israel has not yet been challenged by significant infiltration from neighboring countries, but it is best to prepare for this scenario. Israel is liable to encounter infiltration in the future, whether from a country defined as an enemy (Syria) or from a country with which it has a peace treaty (Jordan). The destabilization of the countries in the region increases the risks of this type and brings with it political and security risks as well.Israel must realize that its standard of living and proximity to conflict-torn areas in the Middle East and Africa expose it to the ongoing risk of illegal immigration. In response to this challenge, Israel must adopt a clear, resolute policy. The failure of Europe in coping with mass immigration should act as a warning as Israel faces the challenge of protecting its character as the nation-state of the Jewish people.The writer is a former minister of interior and education. He currently serves as a senior fellow at the Institute for National Security Studies.