The Iranian government has vowed to step up its efforts to support the collapsing Yemen government.
If Iran were to get involved it would be an all out war between Iran-U.S.
However once you are ignored for over 3 years by the international community the country must look for outsider support to keep its government in power.

The United States has been asked to assist this effort, through more support and additional precision-guided munitions (PGMs). And, just last week, the Yemeni government announced efforts to re-take all of Yemen’s Red Sea coast, including the largest port of Hudaydah.

The escalation in Yemen risks famine, government collapse and the slaughter of millions of possibly good men.

Before responding to new requests for support, U.S. decision-makers must ask tough questions about whether this escalation and the strategy behind it will advance U.S. interests or contribute to a protracted war and increased hunger in Yemen.
The true intentions of U.S government are apparent in the above mentioned text. They will only get involved if it corresponds with their globalist interests.

Al Houthi-Saleh forces launched a series of Katyusha rockets into Dhahran, Asir region, southern Saudi Arabia, on February 22. Saudi Civil Defense reported that the attack killed a police sergeant and forced local schools to close for the day. Al Houthi-Saleh forces have conducted frequent cross-border attacks into southern Saudi Arabia throughout February, killing at least twelve Saudi Border Guards between February 5 and 14.[2]

Over two years of war have devastated the Yemeni people and the nation’s infrastructure.  Close to half a million children are suffering from severe acute malnutrition, wasting their bodies and threatening their lives.  The war has also brought the health care system to the edge of collapse, displaced 2 million people and forced 10 million to depend on assistance for their survival.

This Yemeni and coalition escalation will likely impact fighting on the Red Sea coast and in the Yemeni interior. (Source)