Carlos Lizama Morales was once seen as a hero, but these days he feels he's more of a threat. A superintendent with a major construction company, Lizama oversaw the building of concrete columns, walls and floor slabs as the Pentagon rose from the ashes of Sept. 11 and, with it, his and his workers' fame.

During the long days and nights of difficult labor, Pentagon employees -- civilian and military -- expressed their appreciation with messages taped to their windows: "We will never forget this''; "We love you guys''; "You guys are heroes."

Today Lizama feels altogether different. Speaking at a gathering of Salvadoran immigrants, Lizama articulated the fear of thousands of Salvadorans who reside in the United States with temporary work permits: "We are always thinking whether or not [U.S. authorities] will expel us."

This is the unfortunate reality for people who straddle the line between legitimacy, as contributors to the advancement of society, and illegitimacy, as noncitizens whose temporary legal status makes their families and fortunes vulnerable to the whims of their surrogate hosts. Their work may be wanted, but overall they feel less than welcome.

In Virginia a new law is keeping many Latinos indoors. Aimed at curbing Northern Virginia's growing gang violence, the law enables local police to stop suspected gang members, ask for papers, and check immigration history. Beyond the large legal and philosophical shift that these new powers represent, the immediate impact has been to undermine other safety initiatives.

Police in Fairfax County recently offered a Spanish-language preventive safety class to demonstrate the use of child safety seats. According to a report in The Post, no one showed up because the immigrant community thought the class was a trap to round up Latinos.

While Virginia police and the nation at large struggle to find the proper balance between public safety and the reasonable exercise of individual freedoms, it is worth noting the segment of the United Nations Human Development Index titled "Cultural liberty in today's diverse world."

The reputable annual report has long argued that development is as much a political as an economic matter. And this year it asserts that societies that are more inclusive of minorities come out ahead, while those that are not suffer for it.

In Latin America, where political elites have long ignored indigenous minorities, disenfranchised groups have recently turned to the streets. Nine months ago in Bolivia, for instance, the democratically elected president was forced to resign after an uprising of indigenous people, who represent more than half the population.

In developed countries such as the United States, measures such as those adopted in Virginia do not have such a drastic effect. But they do push immigrants further to the fringes. Immigrants who see their chances to become full members of society diminished turn into what the U.N. report refers to as "ghetto communities." Ghettoizing further exacerbates anti-immigrant and xenophobic feelings on the one hand and economic deprivation and distrust of authorities on the other.

While the report generally avoids criticism of a particular country's current policies, it raises significant and timely questions about the direction in which the United States is heading. Since the Sept. 11 attacks, laws such as the one in Virginia have justified new immigration powers for police based on a security rationale. Their application, however, unquestionably stigmatizes entire groups, particularly noncitizens.

And this is where cultural exclusion gets scary. Perpetuating divisions and stigmatizing groups hurts not only the stigmatized but society as a whole. Immigrants become suspicious of all activity involving police and so become reluctant to turn to them to report crime. In today's world it is precisely that community where governments should want to cultivate confidence. After all, it is among them where the real menaces to society can gain a foothold or simply find a convenient hideout.

Lizama and immigrants throughout the country describe a world where arbitrary acts are becoming commonplace: Legal immigrants are having difficulties obtaining simple forms of identification, drivers are being stopped just for the way they look, day laborers are becoming victims of hate crimes, migrant families are broken apart from one day to the next.

Once loved, Lizama and his workers feel the United States no longer embraces them. What a luxury it is for a society to allow its former heroes to live now in fear.