Alon Liel is a former Israeli ambassador to South Africa and former director general of the Israeli foreign ministry. But when his former office harshly criticized South Africa for enabling a consumer boycott of exports from West Bank settlements in May, Mr. Liel's response sharply diverged from the party line.

In a commentary published in Business Day, a South Africa daily, he sided with the South African government, rejecting the foreign ministry's contention that encouraging the boycott constituted a "racist" policy. With his very public break with government policy, Liel became the rare former senior official to encourage such a boycott.

A consumer boycott serves to reassert the existence of the West Bank border, which Liel argues has been blurred in Israelis' minds by the establishment of Israeli settlements.

"The simple act of marking settlement products differently to Israeli products pulls the rug from under the refusal to declare a border," he wrote. "I buy Israeli products every day and do my best not to buy Israeli products from the Occupied Territories. I don't see why you, living outside Israel, shouldn't have the same choice."

Liel also added his name to a petition by more than 1,000 Israeli academics calling for a local academic boycott of the Ariel University Center. The petition alleges that the school is a vehicle of Israel's right-wing government to make Israel's presence in the West Bank a permanent one, risks an academic boycott of Israeli universities, and calls on AUC students and faculty to transfer to institutions in Israel proper.

Liel argues that at a time when West Bank settlements are expanding, applying pressure to AUC and the dozens of businesses based in industrial parks in the settlements could deliver a "symbolic" blow and persuade some to relocate inside Israel.

However, he draws what he says is an important distinction between a boycott of settlement goods and one that targets all Israeli exports, which is the goal of the international pro-Palestinian Boycott, Divestment, and Sanctions (BDS) movement.

His distinction was rejected by the Israeli parliament, which last year passed a controversial law that set out harsh penalties for anyone promoting boycotts. The text of that law considers targeting West Bank goods, institutions, and individuals tantamount to targeting the same from the entire country.

But so far boycott efforts have had only a negligible impact on the Israeli economy and cultural life, despite their high profile. And despite the fact that he opposes accreditation for AUC, Liel does not share Israeli academics' fears that it would jeopardize research cooperation around the world or undermine the standing of Israeli academia.

Liel remembers from his days as an envoy to apartheid-era South Africa what a full-blown academic boycott resembles: South African academics isolated from their colleagues in most countries, who were told to terminate any links to South Africa (Israel was one of the exceptions).

The former diplomat doesn't see that happening for Israel because he finds it unlikely that the United States and its allies would support such a move. "It isn't having an even negligible effect on Israeli economy or Israeli universities," he says. "I don't think that it can gain serious momentum."