Prime Minister Benjamin Netanyahu is proposing that Kadima chairwoman Tzipi Livni and her party join the governing coalition. Netanyahu has also been threatening Livni that if she turns him down, he will act to break up her party and bring "part of Kadima" into the coalition. Because they remained outside the government when cabinet portfolios were assigned, Livni and her colleagues are being invited to serve as ministers without portfolio, similar to Menachem Begin's role when he joined prime minister Levi Eshkol's cabinet on the eve of the Six-Day War.

Netanyahu's motives are clear. The addition of Kadima to the government will strengthen the coalition's left wing, protect the prime minister from the so-called rebels on the right and increase his government's longevity. It might be asked, however, if a broader governing coalition will also be good for the country.

National unity governments undermine the democratic structure of coalitions and oppositions and deprive the public of an alternative to the government in power. There have been unity governments that dealt with military and economic crises - such as the rampant inflation in the 1980s, the second intifada and the Israeli disengagement from the Gaza Strip - but in most instances, unity was just a cover for diplomatic paralysis and a hesitancy to make decisions.

Netanyahu argues that a broader coalition is essential because of the challenges Israel faces, hinting at the Iranian issue and the diplomatic steps he plans to advance. However, his policies raise the suspicion that he wants Kadima in the coalition to serve as a shield against international pressure, not as a political base for a diplomatic breakthrough.

Netanyahu has counterbalanced the daring decisions he says he has made - most notably support for a two-state solution and a partial freeze on settlement construction - with steps to flatter the settlers and the right wing.

Livni has acted with similar ambiguity as leader of the opposition, and has yet to propose an alternative to the prime minister's policies. She has helped him explain his positions to the world and sufficed with sporadic criticism of his conduct. She appears to be trying to imitate Netanyahu when he was opposition leader during prime minister Ehud Olmert's tenure - refraining from criticism of the government and quietly waiting for it to fall.

Now, however, the former foreign minister faces a decision. If Livni joins Netanyahu's bloated government, she will forfeit any pretension of providing an alternate political approach. There is a rationale in broadening the coalition, if only to advance the peace process - which involves withdrawals, evacuations and confrontations with the right wing. In the absence of such a process, it would be better for Kadima and Israeli democracy if Livni stayed out of the government.